Aquaponics Digest - Tue 03/21/00
Message 1: Re: Duckweed Tomes Found in Garage
from "Steve"
Message 2: Re: (no subject)
from "Steve"
Message 3: Re: Duckweed Tomes Found in Garage
from "Steve"
Message 4: Re: Duckweed Chronicles
from "Steve"
Message 5: Re: Aquaponics Digest - Thu 03/16/00
from "Steve"
Message 6: Re: Fish Food
from "Steve"
Message 7: Re: Duckweed Tomes Found in Garage
from Rboylan2
Message 8: starter
from carnette pulma
Message 9: starter
from carnette pulma
Message 10: more duckweed
from Tony Cooper
Message 11: Re: more duckweed
from "TGTX"
Message 12: (LONG) Summary of previous posts on Duckweed
from S & S Aqua Farm
Message 13: Re: more duckweed
from tvoivozhd
Message 14: Re: Any suggestions
from "Sam Levy"
Message 15: gallon capacity per 100,000 lbs. per year
from "Peter D. Rau"
Message 16: Re: Duckweed Chronicles
from "Sam Levy"
Message 17: Watercress from the archives, was Re: more duckweed
from S & S Aqua Farm
Message 18: Re: gallon capacity per 100,000 lbs. per year
from "James Rakocy"
Message 19: Re: Any suggestions
from "Barry Thomas"
Message 20: Re: Watercress from the archives, was Re: more duckweed
from tvoivozhd
Message 21: Re: gallon capacity per 100,000 lbs. per year
from "Peter D. Rau"
Message 22: duckweed
from John Hays
Message 23: Re: Any suggestions
from "Barry Thomas"
Message 24: Re: gallon capacity per 100,000 lbs. per year
from Ronald Polka
Message 25: market study/business plan was Re: gallon capacity per 100,000 lbs. per
year
from "Peter D. Rau"
Message 26: Re: market study/business plan was Re: gallon capacity per 100,000 lbs. per year
from "James Rakocy"
Message 27: Re: market study/business plan
from "Peter D. Rau"
Message 28: Re: market study/business plan
from "James Rakocy"
Message 29: Re: gallon capacity per 100,000 lbs. per year
from Bertmcl
Message 30: Re: Any suggestions
from "Barry Thomas"
Message 31: Re: Duckweed Chronicles
from "TGTX"
Message 32: Re: more duckweed
from "TGTX"
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| Message 1 |
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Subject: Re: Duckweed Tomes Found in Garage
From: "Steve"
Date: Tue, 21 Mar 2000 00:32:26 -0600
Hi Ted,
I spent considerable time trying to digest the information that you
forwarded on "Duckweed". I think I am a relatively intelligent individual,
but "WOW", can't hold a candle to you.
Have a relatively simple but lengthy question for you: I operate a 1,600 gal
recirc aquaponic system (Tilapia, Romaine lettuce (just getting started),
okra, Jalapeno peppers and a Phillipine long green bean). I have a clarifier
set up between my 2-800 gal tanks (for settling, etc.) I tried water
hyacincths (sp) in the clarifier, but they died. I, as everyone is, am
constantly worried about ammonia/nitrite buildup in the system. (I dump
apprx. 25% of the system every 5-7 days.) Would Duckweed survive and be
productive in the clarifier?
Also, (I lied, I have 2 questions.) I have a 1/3 - 1/4 acre pond that I
raise catfish, bluegills and perch in. (Right now I call it my $6,000
'hole-in-the-ground' after the drought we had in Wisconsin last year. It is
starting to come up slowly though.) The water quality in the pond is
terrible due to "no fresh water". Won't get into that! Would the duckweed
help in sucking out the ammonia/nitrates that are in the pond?
3rd question (JEEZ, I lied again!!), can duckweed be bought if it is really
beneficial?
Thanks for your article.
Later.......Steve
----- Original Message -----
From: "TGTX"
To:
Sent: Sunday, March 19, 2000 12:25 PM
Subject: Duckweed Tomes Found in Garage
> Folks, it's just amazing what you find when you finally decide to clean
the
> garage.
> Sure, it's punishment, but then there's the occasional reward or amazing
> find.
> Along with about 10 years of issues of Mother Earth Magazine, I found
Volume
> 1 and 2 of "The family of Lemnaceae- a monographic study" by Elias
Landolt
> and Riklef Kandeler, 1986 and 1987 (ISSN 0254-9433) Each of these tomes
are
> about 600 pages. Forgot about these....
>
> Here are some interesting factoids I can share while I take a break from
the
> garage thing.
>
> "The maximum growth rate in Lemnaceae is species and clone specific. The
> highest growth rate...corresponds to about a doubling time of 24 hours.
> This was noted in L. aequinoctialis and in W. microscopica. This highest
> growth rate results in an increas of 1 gram per gram dry weight a day, or
64
> grams per gram dry weight a week. In comparison, fast growing corn does
not
> produce more than 2.3 g/g a week."
>
> Productivity of Lemnaceae in the wild varies by reports from about 7 to 39
> tons dry weight per hectare per year.
>
> "Protein content reaches 15 to 45% of dry weight. The lower limit of
> nitrogen concentration in the growth solution resulting in a high %
protein
> is 20-30 mg/L (ppm)."
>
> "Not only the quantity but also the quality of proteins makes Lemnaceae
> economically interesting. With the exception of tryptophane and
methionine,
> all essential amino acids used in human and animal food are satisfactorily
> present. Tryptophane is detected only in traces. Methionine content
varies
> between 0.3% and 3% of the total protein, depending on the clone and it
> varied with investigators....Chang et al (1977) analyzed as much as 3.1 to
> 4.7% methionine, a value which would satisfy the requirements of the FAO"
>
> "The essential amino acid index (EAA) amounts to 76 for Lemnaceae. In
> comparison, the EAA for eggs is reported as 97. The protein efficiency
> ratio for Lemnacea fed to grass carp reached 2.36"
>
> "Considering the high productivity and the high protein content of
Lemnacea,
> the protein yield per area must be higher than that of any other crop
plant.
> If we assume a maximum yield of 50 tons dry weight per hectare / year and
a
> mean percentage of protein harves of 30% of the dry weight, we can expect
a
> protein harvest of up to 15 ton per hectare per year.....Oron et. al.
> indicate that protein yield of duckweed grown in waste water systems may
> reach 12 ton per hectare per year. Soybean...yields up to 0.7 tons
protein
> per hectare per year....about 1/20th of the potential yield of Lemnacea."
>
> Well, there is all kinds of good stuff in here.....Looks like I'll be up
> reading tonight...or is it re-reading...I really don't remember reading
all
> this 2 decades ago, but maybe I did.....Yeah this should keep me awake
> reading tonight.... for about 30 minutes.... until I pass out from all the
> effort in the garage today.
>
> If you folks have any specific questions/ interests that I can field from
> these books, please let me know...there is all kind of stuff on
harvesting,
> animal feed, light conditions, nutrients...yada...yada..
>
> Have a great weekend.
>
> Ted
>
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| Message 2 |
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Subject: Re: (no subject)
From: "Steve"
Date: Tue, 21 Mar 2000 00:39:48 -0600
Hi Bob,
Welcome to the list. As you will probably notice, we are a very
non-prejudiced group of people. We will probably recommend 3 types of fish
for you: 1st is Tilapia, 2nd is the Tilapia and the 3rd if you are tired of
the first 2 is Tilapia. You, as a businessman...such as we all are......can
choose between any of the three.
We will look forward to your comments and input as far as the marketing of
the vegetables goes.
Remember, you have 3 choices of fish, so choose wisely.
Take care..........Steve
----- Original Message -----
From:
To:
Sent: Sunday, March 19, 2000 5:44 PM
Subject: (no subject)
> Hi. I'm a hydroponic grower who has been growing for about 14 years
> commercially. We have three greenhouses and grow herbs , lettuces,
tomatoes
> and cucumbers. I am working at putting in a small aquaponics set in one
of
> my houses with my watercress beds. The tank that I have is approx. one
foot
> deep by 6' x 20'. I'm looking for recomendations for what kind of fish to
> put in this to make it profitable. The house is a cool house -min.
50degrees
> except in the summer it will get pretty warm when the nights stay in the
> upper seventys. I'm in southern PA. We already sell to restaurants so an
> edible fish would work . I also thought about aquariuum or bait fish. I'd
> love to hear your thoughts.
>
>
> Bob
>
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| Message 3 |
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Subject: Re: Duckweed Tomes Found in Garage
From: "Steve"
Date: Tue, 21 Mar 2000 00:41:08 -0600
"Gofurit" Ted,
You're on the clock.
Steve
----- Original Message -----
From: "beacnhrt"
To:
Sent: Sunday, March 19, 2000 7:27 PM
Subject: Re: Duckweed Tomes Found in Garage
> Ted,
> I can not understand why use of such information has not been made over
> the last two decades. It would sure be nice if you could gleen out the
> useful cultural and processing information and pass it along. Lets see at
a
> half hour a night...........how fast do you read?
> melvin landers
> -----Original Message-----
> From: TGTX
> To: aquaponics@townsqr.com
> Date: Sunday, March 19, 2000 12:15 PM
> Subject: Duckweed Tomes Found in Garage
>
>
> >Folks, it's just amazing what you find when you finally decide to clean
the
> >garage.
> >Sure, it's punishment, but then there's the occasional reward or amazing
> >find.
> >Along with about 10 years of issues of Mother Earth Magazine, I found
> Volume
> >1 and 2 of "The family of Lemnaceae- a monographic study" by Elias
Landolt
> >and Riklef Kandeler, 1986 and 1987 (ISSN 0254-9433) Each of these tomes
> are
> >about 600 pages. Forgot about these....
> >
> >Here are some interesting factoids I can share while I take a break from
> the
> >garage thing.
> >
> >"The maximum growth rate in Lemnaceae is species and clone specific. The
> >highest growth rate...corresponds to about a doubling time of 24 hours.
> >This was noted in L. aequinoctialis and in W. microscopica. This highest
> >growth rate results in an increas of 1 gram per gram dry weight a day, or
> 64
> >grams per gram dry weight a week. In comparison, fast growing corn does
> not
> >produce more than 2.3 g/g a week."
> >
> >Productivity of Lemnaceae in the wild varies by reports from about 7 to
39
> >tons dry weight per hectare per year.
> >
> >"Protein content reaches 15 to 45% of dry weight. The lower limit of
> >nitrogen concentration in the growth solution resulting in a high %
protein
> >is 20-30 mg/L (ppm)."
> >
> >"Not only the quantity but also the quality of proteins makes Lemnaceae
> >economically interesting. With the exception of tryptophane and
> methionine,
> >all essential amino acids used in human and animal food are
satisfactorily
> >present. Tryptophane is detected only in traces. Methionine content
> varies
> >between 0.3% and 3% of the total protein, depending on the clone and it
> >varied with investigators....Chang et al (1977) analyzed as much as 3.1
to
> >4.7% methionine, a value which would satisfy the requirements of the FAO"
> >
> >"The essential amino acid index (EAA) amounts to 76 for Lemnaceae. In
> >comparison, the EAA for eggs is reported as 97. The protein efficiency
> >ratio for Lemnacea fed to grass carp reached 2.36"
> >
> >"Considering the high productivity and the high protein content of
> Lemnacea,
> >the protein yield per area must be higher than that of any other crop
> plant.
> >If we assume a maximum yield of 50 tons dry weight per hectare / year and
a
> >mean percentage of protein harves of 30% of the dry weight, we can expect
a
> >protein harvest of up to 15 ton per hectare per year.....Oron et. al.
> >indicate that protein yield of duckweed grown in waste water systems may
> >reach 12 ton per hectare per year. Soybean...yields up to 0.7 tons
protein
> >per hectare per year....about 1/20th of the potential yield of Lemnacea."
> >
> >Well, there is all kinds of good stuff in here.....Looks like I'll be up
> >reading tonight...or is it re-reading...I really don't remember reading
all
> >this 2 decades ago, but maybe I did.....Yeah this should keep me awake
> >reading tonight.... for about 30 minutes.... until I pass out from all
the
> >effort in the garage today.
> >
> >If you folks have any specific questions/ interests that I can field from
> >these books, please let me know...there is all kind of stuff on
harvesting,
> >animal feed, light conditions, nutrients...yada...yada..
> >
> >Have a great weekend.
> >
> >Ted
> >
> >
>
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| Message 4 |
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Subject: Re: Duckweed Chronicles
From: "Steve"
Date: Tue, 21 Mar 2000 01:08:45 -0600
BOY!
You are really into this aren't you? Keep it up Buddy. I read your posts
with interest.
Take care.......Steve
----- Original Message -----
From: "TGTX"
To:
Sent: Monday, March 20, 2000 7:58 PM
Subject: Duckweed Chronicles
> Hi Sam..
>
> I will try to get to the nutrient/mineral uptake questions as we go here.
>
> I will just present a string of factoids as I have highlighted them from
the
> mongraph on duckweed...I will continue on this post this evening until
> fatigue or the carpal tunnel thing starts to evict me from the keyboard...
>
> Starting from Volume 1...(I will use the abbreviation Lemna. to indicate
> Lemnaceae)
>
> Lemna. mostly float on or near the surface of the water. Therefore, they
> are very sensitive to movements of the water caused by current, waves, or
> wind. Lemna plants float in a channel without rooted plants with a
velocity
> of 70-100% of water movement within 0.01 and 0.1 m/sec velocity. In dense
> stands, Lemna are not moved at all if water velocity does not exceed 0.08
> m/s. They can be pushed together in some quiet areas where they can form
> layers up to 20 cm thick. In this case most fronds do not get enough
light
> and nutrients and will eventually die.
>
> Most species of temperate regions are able to survive freezing in ice for
> short periods. Shallow waters (in the wild) are more conducive to Lemna.
> growth, since most nutrients are concentrated near the bottom of the
water;
> the nearer the Lemna cover is to the nutrient pool the better is the
supply
> through diffussion or intermixing...
>
> There are several conditions where Lemna grow outside of a water
body...wet
> muddy shores, test tubes in agar medium..in the drip of waterfalls or on
wet
> rocks..(Think about this in terms of the water wall or garden wall concept
> tauted by some folks on this group) Lemna living in waterfalls hang
closely
> together by the roots. Only species with long roots (L. minor) are able
to
> use this ecological niche.
>
> Lemna. are found in waters of all temperatures except in arctic and
> antarctic climates. Lemna. grow in the hottest regions of the world. The
> highest temp. measured in waters with L. aequinoctialis was 37C in
> ricefields of the Central Valley of California. Optimum temperatures for
> the growth of Lemna. are above 24C for all investigated species. At low
> light intensities, the optimum temperatures are generally lower than at
high
> light intensities or in solutions with sugar. The growth rate at day
temps
> of 26C for 16 hrs and night temps of 14 C for 8 hrs showed only slight
> deviations from the growth rate at a constant temp of 22C. A temperature
> of -10C is probably deadly for all species.
>
> Lemna. can be found in sunny as well as in shady situations. Locally
> adapted species of Lemna. can be found growing in the wild in situations
> where the light intensity at noon does not exceed 500 lux. Lemna. can be
> grown in complete darkness if organic substances such as sugars are added
to
> the nutrient solution. In nature, it is probable that Lemna. are also able
> to supply their energy demands from dissolved organic substances. Light
> saturation varies at24C between 4000 lux and at least 15000 lux. It is
> higher at higher temps and lower at lower temps. It may also be higher at
> shorter illumination periods.
>
> Sodium in waters with Lemna. varies from 1.3 mg/L to more than 1000
> mg/L...This corresponds to salt concentrations of about 0.004 to 2.5
> ppt(???), or temporarilty in water up to 4 ppt(???). The potassium
content
> of waters with Lemna. varies between 0.5 and 100 mg/L...rarely less than 1
> mg/L...90% of localities with L.minor in the Netherlands contained between
> 1.95 and 29.5 mg/L potassium.
>
> Optimal growth of Lemna. in culture was observed in solutions with a
> nitrogen content from 0.6 up to more than 70 mg/L, depending on species.
> Upper limits of nitrogen concentration for growth has been measured at
> 420-2100 mg/L....pretty high levels, indeed!. The 50% inhibitory level
of
> ammonia Nitrogen is 700 mg/L for L. obscura. L. aequinoctilatis showed
> symptoms of toxicity at 1400 mg/L nitrate nitrogen.
>
> Optimal growth of Lemna. in culture is between 0.03 and 10.9 mg/L P for
> various species...This is a wild range here, folks!
>
> Lemna. generally like high values of bicarbonate (mostly between 30 and
200
> mg/L...
> I don't consider 30 mg/L high....but I am just the typist here)
>
> Gotta go.
>
> Have a good evening.
>
> Ted
>
>
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| Message 5 |
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Subject: Re: Aquaponics Digest - Thu 03/16/00
From: "Steve"
Date: Tue, 21 Mar 2000 01:12:51 -0600
Try Wisconsin,
Worst drought in recorded history. My pond (& the Great Lakes) are down
about 7' .....not 7"...but 7'.
That hurts.......good luck to your "mudbugs"...everything goes downhill.
Steve
----- Original Message -----
From: "Jay Myers"
To:
Sent: Monday, March 20, 2000 8:03 PM
Subject: Re: Aquaponics Digest - Thu 03/16/00
> Dave..
>
> We in Panama City Beach also look forward to our Cajun Fest, but it had
been
> canceled this year due to the "Mud Bugs" going up 4x in price due the
thee
> low water. booooooo.
>
> Jay Myers
> Panama City Beach, Fl.
>
>
>
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| Message 6 |
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Subject: Re: Fish Food
From: "Steve"
Date: Tue, 21 Mar 2000 01:19:55 -0600
Hi Ted (again),
I contacted Rangen and I seemed to like them. They faxed me some very good
info. I won't necessarily be saving any $, but it appears their product is
superior to what I have been using.
Thanks again.
Steve
----- Original Message -----
From: "TGTX"
To:
Sent: Sunday, March 12, 2000 11:23 AM
Subject: Re: Fish Food
> > >Does anyone know of a "reputable" source where I can buy fish food?
> > >Would appreciate any help.........Steve
>
> Clements Farm Service P.O. Box 2347 Gibsonton, FL 33534
> Phone 813-677-1627
>
> Burris Mill & Feed, Inc. 1012 Pearl St. Franklinton, LA 70438
> Phone 800 928 2782 or 504 839 3400
>
> Rangen Inc.
> P.O. Box 706 115 13th Ave. South, Buhl, ID 83316 U.S.A.
> 208-543 6421 8006576446
> 1500 East Cedar, Angleton, TX 77515, U.S.A.
> Balrosario S.A., P.O. Box 659, Guayaquil, Ecuador
>
> Zeigler Bros., Inc.
> P.O. Box 95, Gardners, PA 17324
> 800 841-6800
>
> Perdue Specialty Feeds, Inc.
> 139 South First Street
> Catawissa, PA 17829
> 800-358-6595
>
> Nelson & Sons, Inc.
> Nelson's Sterling Silver Cup
> 118 West 4800 South P.O. Box 57428
> Murray Utah 84157-0428
> 801 262 2991 800 521 9092
>
> Integral Fish Foods, Inc.
> 715 South 7th. Street
> Grand Junction, CO 815 01
> 970-242-2798
>
> Southern States Aquaculture Feeds
> Jeff Fagan at 888-677-3474
>
> Purina Mills, Inc.
> P.O. Box 66812
> St. Louis, MO 63166-6812 USA
> 800-227-8941
>
> There are many more, but these are some of the big dogs.
>
> Ted
>
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| Message 7 |
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Subject: Re: Duckweed Tomes Found in Garage
From: Rboylan2
Date: Tue, 21 Mar 2000 02:22:43 EST
In a message dated 3/20/00 10:35:07 PM, careplus@execpc.com writes:
>Would Duckweed survive and be
>
>productive in the clarifier?
I have had good luck growing duckweed in clarifiers. Growth will be limited
by light levels, water temperature, and water turbulence.
>Also, (I lied, I have 2 questions.) I have a 1/3 - 1/4 acre pond that
>I
>
>raise catfish, bluegills and perch in. (Right now I call it my $6,000
>
>'hole-in-the-ground' after the drought we had in Wisconsin last year. It
>is
>
>starting to come up slowly though.) The water quality in the pond is
>
>terrible due to "no fresh water". Won't get into that! Would the duckweed
>
>help in sucking out the ammonia/nitrates that are in the pond?
To an extent, yes. I don't have any data in front of me right now, but I do
recollect that the duckweed in the various Living Machine systems (both
aquaculture- and wastewater- oriented) pulled out more ammonia than other
plants on a per-meter-squared basis, but of course the main ammonia
reductions occurred in the fixed-film biofilters/gravel beds/ and the like.
Duckweed grows best when it is not disturbed by wind. If your pond is on a
windy site, you may want to construct a partition-grid of baffles on the
surface, and going down 2"-3" below the water. Three-foot squares work pretty
well. You can then harvest half of each square's duckweed as you need it, and
easily observe the rate of doubling for your particular species and growing
conditions.
Hope this helps,
-Richard
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| Message 8 |
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Subject: starter
From: carnette pulma
Date: Tue, 21 Mar 2000 01:08:35 -0800 (PST)
Dear all:
Greetings!
I would like to know the starting materials to
build an aquaponic system for an area of 1000 sq.
meter ?
I hope you can help me. Thank you very much.
Carnette C. Pulma
carnettepulma@yahoo.com
__________________________________________________
Do You Yahoo!?
Talk to your friends online with Yahoo! Messenger.
http://im.yahoo.com
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| Message 9 |
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Subject: starter
From: carnette pulma
Date: Tue, 21 Mar 2000 01:10:19 -0800 (PST)
Dear all:
Greetings!
I would like to know the starting materials to
build an aquaponic system for an area of 1000 sq.
meter ?
I hope you can help me. Thank you very much.
Carnette C. Pulma
carnettepulma@yahoo.com
__________________________________________________
Do You Yahoo!?
Talk to your friends online with Yahoo! Messenger.
http://im.yahoo.com
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| Message 10 |
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Subject: more duckweed
From: Tony Cooper
Date: Tue, 21 Mar 2000 18:20:43 -0800
Glad to see the duckweed thread going as i am doing a growing trial
with it right now.
I collected some along the edges of a nearby stream and divided it into
two 3 ft square trays, one with water from the tilapia tank and one with
a weak hydroponic solution EC 0.7, both filled 2 inches deep and placed
in a sunny area.
At first, growth was slow perhaps due to stress but now i get a doubling
of volume in 2 days. When the surface of the tray is covered to the
point that no water is visible i place a divider across the center of
the tray and remove the weed from one side then take out the divider,
two days later its full again. Day temperature is about 31 Celsius in
the shade [Location; Luzon, Philippines] the local strain doesn't
multiply in the shade.
I also got some azolla and did the same trials, the sample in the
hydroponic nutrient grew well doubling in three days but in the tilapia
water it is slowly dying with no new growth.
My interest in duckweed and azolla is to use them for tilapia feed and
my fingerlings can't seem to get enough of either, [chickens too]
however to maximize the protein intake i will have to dry it as it is
about 90% water by weight and fish don't get fat on that.
Ted,
what do your books have to say about fish feed formulations?
Tony Cooper.
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| Message 11 |
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Subject: Re: more duckweed
From: "TGTX"
Date: Tue, 21 Mar 2000 06:44:20 -0600
> Ted,
> what do your books have to say about fish feed formulations?
>
Tony Cooper.
Will get back to you this evening on that.
Gotta go.
Ted
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| Message 12 |
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Subject: (LONG) Summary of previous posts on Duckweed
From: S & S Aqua Farm
Date: Tue, 21 Mar 2000 07:29:52 -0600
In order to perhaps save Ted some time spent restating (from his books) what
had already been sent to the list in the past, I've gathered some of the
earlier posts and summarized them below. Sorry if I've missed any
contributions that are under another subject heading. Paula (BTW, I
checked out the web site mentioned in Darren's post below, and it is still
active.)
--------------------------
Date: Sun, 14 Dec 1997 11:58:42 -0800 (PST)
To: aquaponics@townsqr.com
From: "Darren J. Hanson"
Subject: Re: Duck Weed
At 10:36 AM 12/14/97 EST, FranksFarm wrote:
>Does any one know the feed value, nutrient contents of such and how to
>incorporate such product into a balanced fish meal ration without having to
>resort to expensive machinery?
The main problem with processing duckweed appears to be its high water content
from what I've read. (90-95%), but it seems to be fiarly nutritions (42%
protein dry
weight, several important amino acids, lots of caroteins, etc.)
Also, with the Carp Polyculture I was reading about, one type of carp ate
the duckweed
and was approximately 50% efficient at converting it's nutrients to its own
use. A second
species was then stocked that fed on feces in the pond to scavange those
remaining
nutrients. It's fecal matter then replaced the raw manure to feed algae and
other
micro-organisms which other carp species fed on.
If anyone is interested, I could try and find the URL again.
----------------------------------------
Date: Sun, 14 Dec 1997 12:54:41 -0800 (PST)
To: aquaponics@townsqr.com
From: "Darren J. Hanson"
Subject: Duck Weed
The URL I mentioned is: http://www.prism-usa.org/fulltext/duckweed/duckweed.htm
And this is the table of contents "page". Happy reading!
TECHNICAL WORKING PAPER
DUCKWEED AQUACULTURE
Table of Contents
--------------------------------
Date: Mon, 15 Dec 1997 23:08:18 -0500
From: Jack Rowe
Subject: Re: Duckweed
To: Aquaponics List
Duckweed is very good at pulling nitrogen (and probably other nutrients)
from water and so is rich by most standards. It would be useful for water
purification, but the nutrients might as well go into veggies. In the
interesting Carp Polycultures mentioned by Darren (thanks for the duckweed
URL and synopsis, Darren!), grass carp utilize the duckweed (50% conversion
efficiency... wow. At 42% protein, it's believable). I don't think we have
analogous, commercially-important herbivorous fish in N. America, though.
Grass carp can be imported into US only if they are sterilized, since they
might cause great disruption in our waterways if they escaped. Sterile
Grass Carp might still be useful for some kind of weed control but could be
expensive (haven't ever priced them). A paranoid aside: How do they (the
ubiquitous 'they') sterilize them?
The Asian Carp Polycultures are amazing -- a brilliant (and long-term)
exercise in human/'livestock' co-evolution to maximize utilization of
wastes and trophic levels.
Jack
0-----------------------------------
Date: Sun, 10 May 1998 14:52:59 -0600
To: aquaponics@townsqr.com
From: John Shannonhouse
Subject: Re: Environmental Aspects of Aquaponics
Hello,
On 8 May 1998, Ted ground wrote:
<>
http://www.prism-usa.org/fulltext/duckweed/duckweed.htm
I found this site extremely informative.
<>
An advantage of duckweed (if you want to use it) is that its
preferred nitrogen source is ammonium. As long as the water's pH is
slightly acid, the duckweed will grow very quickly in wastewater and
effectively scrub it of nutrients. Since it floats on the surface, no
aeration is needed. The faster it grows, the higher its quality is. A
well-managed system will efectively shade out algae. It makes a complete
feed for Tilapia or common carp (and ducks, I think), but they probably
won't achieve a near-maximal growth rate because the feed is over 90% water
(if Dr. Rakcocy's hypothesis is correct about the reason Tilapia grow
slowly on algae is that they need to purge themselves of excess water in
their feed).
For the purposes of the system described, the primary disadvantages
are that duckweed cannot be stored for extended periods of time, the
effluent that the duckweed uses must be free of toxic heavy metals (though
this is true for any agricultural system using wastewater, I imagine) and
the high level of carotenoids, which makes it unsuitable for certain
livestock such as cows (it changes the meat's color to unattractive hues).
Based on my admittedly limited knowledge, I would recommend
skipping the Spirulina and going straight through a duckweed "scrubber"
stage instead to avoid eutrophication, then flowing into you Tilapia ponds.
Unlike the figures from your Lativian collegues, the specific yields and
growth conditions of duckweed are available (and they look impressive to
me).
John Shannonhouse
------------------------------------
From: "Ted Ground"
To:
Subject: Re: Duckweed as Feed
Date: Sun, 10 May 1998 17:36:43 -0500
John,
Thanks for the report on duckweed.
I have some questions for you. How would you suggest "packaging" the
duckweed for fish food- from fingerling to harvest size. That is, could
one:
1)let the little fish and the big fish eat the duckweed in a kind of hands
off, natural pond, as the duckweed grows in the same culture pond that the
fish are growing in? And if so, does duckweed alone meet all their dietary
needs?, OR
2) grow fish in a separate pond, and toss into the fish tank weighed, daily
rations of duckweed which has been grown in a separate pond? OR
3) Harvest the duckweed and somehow grind, blend, or concentrate it into a
pellet, perhaps add a few things in the process, like worms, to make
delicious fish gruel?
The fingerlings dietary needs seem to be different than the big dudes, if
only in the way of particle size, so how would you address that?
Keep on Brainstormin',
Ted
-------------------------------------------
Date: Mon, 11 May 1998 09:59:32 -0600
To: aquaponics@townsqr.com
From: John Shannonhouse
Subject: Re: Duckweed as Feed
Ted,
You have to take my suggestions with a grain of salt. Everything I
am about to say is based on what I havbe read, not on any experience.
<<1)let the little fish and the big fish eat the duckweed in a kind of
hands off, natural pond, as the duckweed grows in the same culture pond
that the fish are growing in? And if so, does duckweed alone meet all their
dietary needs?>>
According to the duckweed aquculture website, duckweed is a
complete feed for Tilapia and common carp. That means the fish will grow
up on nothing else. Duckweed alone may limit their growth, though.
I would not suggest using a natural pond. The duckweed really grow
fast when there is a lot of ammonium in the water (they have a chart about
this on the website, I believe). This may make the levels of ammonia high
enough to be unhealthy for the fish.
<<2) grow fish in a separate pond, and toss into the fish tank weighed,
daily rations of duckweed which has been grown in a separate pond?>>
I would guess this is better than the first option. That is how
the experimenters did it.
<<3) Harvest the duckweed and somehow grind, blend, or concentrate it into
a pellet, perhaps add a few things in the process, like worms, to make
delicious fish gruel?>>
I would guess that this would be the best option. You could mix it
with something drier and maybe compensate for limiting nutrients in
duckweed.
Your questions would be best addressed by experimentation comparing
the three processes.
<>
Crumble up the duckweed in a mortor before you drop it into the tanks?
John Shannonhouse
----------------------------------------
From: "Ted Ground"
To:
Subject: Re: Duckweed as Feed
Date: Mon, 11 May 1998 15:29:27 -0500
John,
Good common sense answers about the duckweed.
You know, I should not have been so lazy- I should have checked that
website out before I asked you all those dumb questions in my last post. I
just went back and checked the duckweed aquaculture website- really good
stuff there- and it was not the website I recall having seen before. I
actually had another one in mind- it is devoted to the use of duckweed for
water treatment, etc. I'll find it later and send that link to the group
if it looks like it might be useful.
Anyway, it is clear that the nitrogen must come from someplace outside the
system when using duckweed as the plant-based feed, and in Uwe's case, it
would be the reaerated anaerobically digested waste. Hmm.. Interesting
stuff. Thanks, John. In the future, I promise to review your recommended
sites before I start asking questions!
Ted
-------------------------------------------
Date: Fri, 15 Oct 1999 08:57:20 -0700
From: dbenhart@essex1.com (David Benhart)
To: aquaponics@townsqr.com
Subject: duckweed
have a small pond that is covered with duckweed. can this be fed to my
talapia?
dave
shore acres greenhouses
-------------------------------------------
From:
To: aquaponics@townsqr.com
Date: Fri, 15 Oct 1999 10:09:07 + 5 EST
Subject: Re: duckweed
Dave,
We tried to grow some duckweed for experiments in my Biology class with my
students in our tilapia tanks - had to cancel the lab
because they destroyed it all and they ate every last drop! So, my gut
instinct is to say "Yes, feed them!" (although in here I am
usually proven wrong)
Mike
---------------------------------------
From: "Ronald W. Brooks"
To:
Subject: RE: duckweed
Date: Fri, 15 Oct 1999 13:40:14 -0400
They relish the stuff. Every once in a while I would give the breeders a
treat of this. It was gone in minutes.
Ron
The One Who Walks Two Paths
------------------------------------------
Date: Sat, 16 Oct 1999 01:23:49 -0400
From: Dave Miller
To: aquaponics@townsqr.com
Subject: Re: duckweed
I remember reading a much earlier post where fish emulsion went to
hydroponics, hydroponics went to a duckweed pond then back to the fish.
And yes, the duckweed was to feed the fish but also use the excess
nutrients from the hydroponics system if I remember correctly.
Ted, Jim, Adriana, Gordon can you remind us here?
--
---------------------------------------------------------
From: "KevinLReed"
To: "S&S Aquaponics"
Subject: Duckweed,Snails and Carbs
Date: Mon, 17 Jan 2000 20:24:20 -1000
Aloha,
Reg Preston's work with Duckweed shows he can get up to 40% protein with a
good nitrogen source to grow it. Dr. Preston uses biodigestor effluent from
his $10 biodigestor units to feed his Duckweed ponds. I have found a
breakdown for nutrition from snails. Note the 79 grams of water. If the
Duckweed, snails and carbs are combine this will make a good fish food....
yes? Doesn't this look like it will make a good balance effluent too?
Kevin
Apple Snail
The nutrient composition of raw snails (per 100 grams of edible portion),
according to information from the nutrient databank
of France, is:
Energy (kcal): 80.5
Water (g): 79
Protein (g): 16
Available carbohydrates (g): 2
Fibers (g): 0
Fat (g): 1
Magnesium (mg): 250
Calcium (mg): 170
Iron (mg): 3.5
Vitamin C (mg): 0
-------------------------------
From: "KevinLReed"
To: "S&S Aquaponics"
Subject: Lemna -" Duckwwed" as protein suppliment
Date: Tue, 21 Dec 1999 18:42:57 -1000
Aloha ( God I love writing that!),
I see the GE controversy rages on ........
In the mean time ...
I found some data about protein content and quality for duckweed.
It seems except for the fact that duckweed has higher fiber content than soy
beans
( and therefore some negligible reduced ability to be digested ) that
duckweed is equal to
soy as far as protein content.
If you have available sources of sugars and lipids in your respective areas
of the world, it may be that working duckwed into the fish diet might be
beneficial to the bottom line. Can anyone say free fishfood? I will be
trying to find the complementary sources to round out Lemna as a protein
suppliment with what is locally avaiable but I think a protein source as
good as soy is a very good start.
GOOD ONE BERT!!!!
Below is URL for a duckweed protein quality study
http://www.fao.org/ag/aga/agap/frg/LRRD/LRRD9/2/ANH92.HTM
Kevin
Anahola, Kauai, HI
------------------------------------------------------
Date: Wed, 22 Dec 1999 11:07:46 -0500
From: "Mark Brotman"
To: aquaponics@townsqr.com
Subject: Re: Lemna -" Duckwwed" as protein suppliment
Kevin,
Duckweed is an excellent choice. You may also wish to take a look at R.
LeRoy Creswell's "Aquaculture Desk Reference" for the nutrient contents
of many other plants that could complement the duck weed. Chapman and
Hall publishers, 1993. It's an outstanding reference on many othe
topics as well.
Aloha fo'i ma a hiu hou,
Mark
KevinLReed wrote:
> Part 1.1 Type: Plain Text (text/plain)
> Encoding: quoted-printable
--
Mark J. Brotman
Aquaculturist
CropKing
------------------------------------------------
Return-path:
From: "KevinLReed"
To: "S&S Aquaponics"
Subject: profitable Azolla or Duckweed
Date: Tue, 18 Jan 2000 10:26:58 -1000
Could the aquaponics technique PROFITABLY benefit from this
procedure? Could a liquid compost lagoon be used to generate
Azolla, Duckweed and a blend of other commercially
unattractive plants that could then be converted/processed
into a balanced fish food?
Marc
The UTA Rural Farm Program in Cambodia is using pond for growing Duckweed to
feed livestock. They also grow some fish in these ponds but primarily they
are to grow Duckweed as a protein supplement for feed. They use biodigestor
effluent material to "feed" the ponds so there is no problem with pathogens.
I will be using separate " rain barrels" that get run off water from the
tarp covering my fish tanks to grow Duckweed. I gather that there are
problems growing Azolla and Duckweed as they compete. The idea is a small
separate system to grow the fish food, then the fish food is used in the
Sperano system to feed the fish. This should offer at least a 40% reduction
in overall cost input if fish feed is truly 40% to 70% of the ongoing cost
of an aquaculture system. If the Sperano system is profitable paying normal
prices for fish food it follows that this will increase profits.
Aloha,
Kevin
-----------------------------------------
Date: Tue, 18 Jan 2000 14:49:37 -0700
From: Marc & Marcy
To: aquaponics@townsqr.com
Subject: Re: profitable Azolla or Duckweed
> Kevin Wrote:
..snip..
> I gather that there are
> problems growing Azolla and Duckweed as they compete.
..snip..
I believe it was something that resembled Azolla
Filiculoides I used in my pond a few years back. It grew
like a long distance bill between separated teenage lovers.
The other plants were smothered in an inch or so thick
carpet of it. I had to remove it by the buckets each week
during peak summer growing. Underneath, however, was the
nicest pond water and algae free pretty green aquarium ready
plants you could imagine. The fish almost glowed with
health. As you said, the duckweed was no competitor.
Thanks for the ideas.
Marc
-----------------------------------------------------
S&S Aqua Farm, http://www.townsqr.com/snsaqua/
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| Message 13 |
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Subject: Re: more duckweed
From: tvoivozhd
Date: Tue, 21 Mar 2000 08:58:55 -0500
Tony Cooper wrote:
> Glad to see the duckweed thread going as i am doing a growing trial
> with it right now.
> I collected some along the edges of a nearby stream and divided it into
> two 3 ft square trays, one with water from the tilapia tank and one with
> a weak hydroponic solution EC 0.7, both filled 2 inches deep and placed
> in a sunny area.
Tvoivozhd---I monitor this group, but don't dip in often because I am
already flooded with e-mails, and more interested in duckweed as a polisher
for sewage treatment.
However, does anyone possess statistics on the growth of watercress? I have
a pond forty feet above my gardens that I use for gravity irrigation. The
pond contains a lot of duckweed, but the more rapidly moving stream in and
out of the pond is full of watercress---storm torns strands of which have
created islands of watercress for miles downstream.
I'm pretty sure watercress would appeal to tilapia, its growth accellerated
by the nutrients y'all are trying to get rid of, and if your market is the
chefs of upper crust hotels and restaurants, watercress should have a ready
market for garnishes, soups and salads.
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 14 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Any suggestions
From: "Sam Levy"
Date: Tue, 21 Mar 2000 06:52:14 PST
>
, looking into the possibilities of dividing the
>tank into sections might be worthwhile? With a centrally drained, round
>tank the partitions might be arranged radially - pivoting on a combined
>drain filter and support post so that the volume of each segment can be
>altered to match the mass of fish it contains. Such a system would
>appear to offer a significantly higher average capacity. What is/are the
>drawback/s?
>
>Barry
barry,
it's prbably simpler to build cages (or hapas) that will sit inside the tank
(or float). the problems are usually cleaning the tank and getting adequate
water flow through the cages. the netting itself will also foul after a
bit.
sam
>
>
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| Message 15 |
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Subject: gallon capacity per 100,000 lbs. per year
From: "Peter D. Rau"
Date: Tue, 21 Mar 2000 08:58:42 -0600
Anyone have a formula for how many gallons of tank space you need per 100,000
lbs. of fish per year produced?
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 16 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Duckweed Chronicles
From: "Sam Levy"
Date: Tue, 21 Mar 2000 07:02:45 PST
thanks, ted--
the salinity tolerance was a bit confusing (1000 mg of Na/liter is the
equivalent of 2.5 ppt if the only salt present is NaCl--but maybe that's
where the 4 ppt came from)--but i assume that's what it said & you"only
typed it."
if you come across any reference to boron in your further adventures, i'd
like to know (in our area we have wasterwater available that occaissionally
runs "high" in boron)
sam
>Sodium in waters with Lemna. varies from 1.3 mg/L to more than 1000
>mg/L...This corresponds to salt concentrations of about 0.004 to 2.5
>ppt(???), or temporarilty in water up to 4 ppt(???).
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 17 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Watercress from the archives, was Re: more duckweed
From: S & S Aqua Farm
Date: Tue, 21 Mar 2000 09:45:23 -0600
At 08:58 AM 03/21/2000 -0500, Tvoivozhd wrote:
>
>However, does anyone possess statistics on the growth of watercress? I have
>a pond forty feet above my gardens that I use for gravity irrigation. The
>pond contains a lot of duckweed, but the more rapidly moving stream in and
>out of the pond is full of watercress---storm torns strands of which have
>created islands of watercress for miles downstream.
>
>I'm pretty sure watercress would appeal to tilapia, its growth accellerated
>by the nutrients y'all are trying to get rid of, and if your market is the
>chefs of upper crust hotels and restaurants, watercress should have a ready
>market for garnishes, soups and salads.
Here's part of some previous info on watercress. Since it's all from 1999,
I believe you could review the archive files to see if there's something
else around that time frame that I missed. The archives, as they stand to
date, are at http://www.i55mall.com/aquaponics/ Paula
----------------------------------------
From: "KevinLReed"
To: "S&S Aquaponics"
Subject: Any watercress data?
Date: Tue, 29 Jun 1999 19:30:12 -0700
Hi,
Since your trial found that the tilapia like watercress. I was wondering if you
might have an idea of what percentage of your growing space might be needed
to feed the fish if planted in watercress? How much space for 2:1 feed to
final fish
weight? How close to a "perpetual motion" greenhouse?
Kevin
-------------------------------------
From: "Ronald W. Brooks"
To:
Subject: RE: Any watercress data?
Date: Wed, 30 Jun 1999 10:11:31 -0400
Good question , And the answer is
I don't know
I have been looking at types of greens to feed my Tilapia to supplement
feedings
The only real reason I thought of watercress is the fact that I have a 2 X 3
foot section of the veggie filter of my 5000 gallon Koi pond planted with
it. The koi greedily jump and pull any stragglers into the pond so they can
munch it down
I also harvest string algae that builds up in the Koi pond for the Tilapia
I have noticed that they have a better appetite for pelleted feed with a
little bit of fresh plant matter daily.
Adriana I have never noticed a bitter taste from my watercress
----------------------------------------
Date: Wed, 30 Jun 1999 10:38:12 -0400 (AST)
To: aquaponics@townsqr.com
From: james.rakocy@uvi.edu (James Rakocy, Ph.D.)
Subject: Re: Any watercress data?
This is not the ratio you want, but I have studied the production of
watercress in an aquaponic system and these are my results:
Yield - 2.7 kg/m2 wet weight
0.15 kg/m2 dry weight
Productivity - 18.5 g/m2/day wet weight
1.0 g/m2/day dry weight
0.05 g/m2/day for nitrogen uptake
Dry weight - 5.4%
Nitrogen - 4.6% of dry weight
Crude protein - 29.0% of dry weight
These are means of three outdoor systems in Alabama during the summer, May
21 - Oct. 11
Jim R.
--------------------------------------------
From: "James Bell"
To:
Subject: Re: Any watercress data?
Date: Wed, 30 Jun 1999 22:39:13 -0400
notice date is correct just trying to get to the millennium
quicker
I am wondering if it is a smart idea trying to use the
resources of the grow beds to feed the fish as I seem to get
the impression that grow beds are where your profit comes from.
I like gravel beds but do realize that they have limitations.
I wonder if it would be feasible to have water go from fish tank
to gravel beds then to a raft system then back to fish tank
question is would there still be sufficient nutrient load in the
water to make the rafts work
also seems the tilapia like 80 deg water how would that affect
lettuce
------------------------------------
Date: Wed, 30 Jun 1999 15:44:21 -0500
To: aquaponics@townsqr.com
From: khale@ballistic.com
Subject: RE: Any watercress data?
> talapia love the leaf off turnip greens- Ken Hale (Texas Talapia Farmer)
-----------------------------------------
From: "vpage"
To:
Subject: Re: Any watercress data?
Date: Wed, 30 Jun 1999 22:19:07 -0600
For the watercress and spinach you don't need even a raft system. If the
plant is stable for initial growth (2") (gravel will do) then it will take
care of itself in tilapia waste water. You will be hacking your way through
it and feeding it to the ducks and geese as well. The water is denitrified
and saturated with oxygen. Larger lettuce shows some signs of iron
deficiency but my "designer lettuces" were harvested at 2-3" before it could
affect them. Dr. Rakocy can answer these questions a lot better than I can.
Victoria
---------------------------------
From: "TGTX"
To:
Subject: Re: Any watercress data?
Date: Thu, 1 Jul 1999 19:17:00 -0500
Watercress grows wildly in my system. I have not grown it in some time.
Can't recall the reaction of the tilapia to it when I threw it in the fish
tank,
but as I recall, they ate it all.
Ted
--------------------------------------------
Date: Fri, 02 Jul 1999 07:31:35 -0400
From: Adriana Gutierrez & Dennis LaGatta
To: aquaponics@townsqr.com
Subject: Re: Any watercress data?
Ted,
Where have you been hombre? It's been mighty quiet in your neck of the
woods. Will your watercress grow in hot weather? I had always assumed
it wouldn't be happy in the sub-tropics.
Adriana
-------------------------------
From: "William Brown"
To:
Subject: Re: Any watercress data?
Date: Fri, 2 Jul 1999 06:19:18 -1000
Watercress grows quite well in Hawaii, but it seems they use free flowing
cool mountain water to get the job done.
William Brown mahiwai@cmpmail.com
(aka lettuce@hilo.net)
--------------------------------------
From: "TGTX"
To:
Subject: Re: Any watercress data?
Date: Fri, 2 Jul 1999 20:53:08 -0500
Howdy, mam'e.
Ive been running around doin stuff, but I try to keep an ear to my favorite
discussion group when I can. "Life is what happens while your busy making
other plans"
Watercress grew pretty well in the hot weather...this was last year...I
tried several varieties...I like the taste and the growth....but I think it
needs to be marketed separately...sort of like marketing your single product
of beet leaf.
See ya.
tedzo.
-----------------------------------
Now I know that's not all the watercress info we have, because I remember
polling the list for anyone willing to supply a wholesaler who was selling
dried product in huge quantities. I'll probably have to hunt back through
the other file -- "crops" instead of "fish feed", although we have used our
watercress for both. I'll post more if I have time to find it.
Paula
S&S Aqua Farm, http://www.townsqr.com/snsaqua/
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| Message 18 |
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Subject: Re: gallon capacity per 100,000 lbs. per year
From: "James Rakocy"
Date: Tue, 21 Mar 2000 11:50:23 -0400
If the final density was 0.5 lbs. per gallon, you would need 200,000
gallons. However, you can produce two crops per year, so the required tank
space would be 100,000 gallons, and there are stock management systems that
can reduce the water requirement further. That is rearing tank space only
and doesn't include water used in the wastewater treatment tanks and the
hydroponic component . Jim R.
----- Original Message -----
From: Peter D. Rau
To:
Sent: Tuesday, March 21, 2000 10:58 AM
Subject: gallon capacity per 100,000 lbs. per year
> Anyone have a formula for how many gallons of tank space you need per
100,000
> lbs. of fish per year produced?
>
>
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| Message 19 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Any suggestions
From: "Barry Thomas"
Date: Tue, 21 Mar 2000 15:54:29 -0000
> There are a number of inherent problems with dividing a
> circular tank. The most critical being the interruption
> and short-circuiting of the flow. When you divide a
> circular tank into a pie, the water inflow enters into one
> piece of the pie.
Yes, if you make it so. Assuming the tank had only 4 to 6 segments
(eight seems too many?) then dividing the inflow between them would seem
reasonably easy - multiple sprayheads mounted either on the wall of the
tank or the central post for example.
> Generally, it is easier for the water to flow directly to
> the drain than to flow through the screen into the next pie
> section. You could adjust the center drain so that is can
> only drain out of the last pie section, but you would still be
> left with disrupted flow dynamics resulting in problems in
> some sections with waste removal and water flow.
I see your point but wasn't really thinking in terms of the water
flowing through the screens (except in an emergency eg. blocked
in/outlet) - if each segment has it's own inflow, it's behaviour ought
to be close to that of a single tank?
> If only one tank is to be used, then a rectangular tank
> can be divided easily and water is forced to flow from
> section to section in order to get to the drain.
But the water quality must deteriorate along the length of the tank - I
would guess you don't get many smiles from the fish reared in the
segment closest to the drain?
An inlet and outlet per segment seems desirable but more
difficult/expensive to achieve in this case? Hardly impossible but I
mentioned the round tanks first as they seemed slightly easier.
> In my experience, with Tilapia, the feces is mostly
> negatively buoyant and a rectangular tank flushes
> wastes as efficiently as circular tanks. This is only
> true if densities are maintained at greater than
> 25 kg/cubic meter (0.2lb/gal.).
> Chris Weaver
As the volume of the segments are varied to match the size of the fish,
this requirement can be reduced?
Barry
barrythomas@btinternet.com
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| Message 20 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Watercress from the archives, was Re: more duckweed
From: tvoivozhd
Date: Tue, 21 Mar 2000 11:06:44 -0500
Tvoivozhd---thanks, Paula
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 21 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: gallon capacity per 100,000 lbs. per year
From: "Peter D. Rau"
Date: Tue, 21 Mar 2000 10:38:48 -0600
What is the yearly production of a the average mid-sized facility? I'm trying
to find a target to base my business plan around. Once I establish what I want
my fish production at, I think that I can accurately determine what my plant
production should be at to break even.
Are most facilities producing herbs/vegetables as the main crop and utilizing
tilapia production as a secondary crop?
If anyone can recommend some books that will answer these type of questions and
help with establishing an aquaponics business plan, I'd appreciate it very
much.
Regards,
Peter
James Rakocy wrote:
> If the final density was 0.5 lbs. per gallon, you would need 200,000
> gallons. However, you can produce two crops per year, so the required tank
> space would be 100,000 gallons, and there are stock management systems that
> can reduce the water requirement further. That is rearing tank space only
> and doesn't include water used in the wastewater treatment tanks and the
> hydroponic component . Jim R.
>
> ----- Original Message -----
> From: Peter D. Rau
> To:
> Sent: Tuesday, March 21, 2000 10:58 AM
> Subject: gallon capacity per 100,000 lbs. per year
>
> > Anyone have a formula for how many gallons of tank space you need per
> 100,000
> > lbs. of fish per year produced?
> >
> >
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| Message 22 |
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Subject: duckweed
From: John Hays
Date: Tue, 21 Mar 2000 09:50:48 -0700
I found this address on the internet
www.prism-usa.org/fulltext/duckweed/duckweed.htm
Good luck
John Hays
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| Message 23 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Any suggestions
From: "Barry Thomas"
Date: Tue, 21 Mar 2000 17:36:38 -0000
Just noticed that I wrote:
... appear to offer a significantly higher average capacity. ...
Should have been:
... appear to operate at a significantly higher average percentage of
capacity. ...
Sorry.
However it seems that the actual capacity might be raised slightly as
well (compared to multi-tank system)?
Barry
barrythomas@btinternet.com
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| Message 24 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: gallon capacity per 100,000 lbs. per year
From: Ronald Polka
Date: Tue, 21 Mar 2000 12:02:22 -0700
At 10:38 AM 3/21/2000 -0600, you wrote:
>What is the yearly production of a the average mid-sized facility? I'm
trying
>to find a target to base my business plan around. Once I establish what I
want
>my fish production at, I think that I can accurately determine what my plant
>production should be at to break even.
>
>Are mos4t facilities producing herbs/vegetables as the main crop and
utilizing
>tilapia production as a secondary crop?
>
>If anyone can recommend some books that will answer these type of
questions and
>help with establishing an aquaponics business plan, I'd appreciate it very
>much.
>
>Regards,
>
>Peter
>
Peter
In writing a business plan for a commercial facility prior to system
sizing it may be prudent to conduct a thorough market study. Determine how
much product at what prices can be sold on a regular basis. If you are
planning on financing a commercial faciliity then it is important to get a
good handle on this part of the planning process because your lending
institution will demand this information. Many growers and aquaculturists
have found themselves in the unenviable position of having market ready
product that they cannot unload. Once you have a good idea of what you can
sell then sizing of your facility will be easier and will be based on a
good business model.
Ron Polka
Southwest Technology Development Institute
New Mexico State University
Box 30001, Dept 3SOL
Las Cruces, NM 88003
rpolka@nmsu.edu
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| Message 25 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: market study/business plan was Re: gallon capacity per 100,000 lbs. per
year
From: "Peter D. Rau"
Date: Tue, 21 Mar 2000 13:42:24 -0600
Ron,
I agree and plan to do such. I live in New Orleans and have found that many
restaurants and supermarkets are providing Tilapia to their customers. All of
the responses to my inquiries result in the same response - pre-frozen, imported
(mostly from South America).
There are hundreds of restaurants here that use only fresh fish. Due to our
proximity to the Gulf of Mexico, that hasn't been a problem in the past. Recent
regulations on some of the fish more commonly used have put many of these
restaurants in a bind. Based on what I've seen, a percentage of them may be open
to trying fresh Tilapia.
I am developing a market survey to determine the overall attitude about the use
of Tilapia, about having fresh Tilapia available, and about having pesticide free
herbs/vegetables available.
I'd also like to explore the possibilty of providing live Tilapia.
Prawn interest me as well, but I don't know what the market possibilities are
since the only restaurants here that serve them are Asian types as sushi.
I have several prospective investors and also am looking into working with the
fisheries programs at several local universities for possible work
study/internship programs.
Regards,
Peter
> Peter
> In writing a business plan for a commercial facility prior to system
> sizing it may be prudent to conduct a thorough market study. Determine how
> much product at what prices can be sold on a regular basis. If you are
> planning on financing a commercial faciliity then it is important to get a
> good handle on this part of the planning process because your lending
> institution will demand this information. Many growers and aquaculturists
> have found themselves in the unenviable position of having market ready
> product that they cannot unload. Once you have a good idea of what you can
> sell then sizing of your facility will be easier and will be based on a
> good business model.
> Ron Polka
> Southwest Technology Development Institute
> New Mexico State University
> Box 30001, Dept 3SOL
> Las Cruces, NM 88003
> rpolka@nmsu.edu
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 26 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: market study/business plan was Re: gallon capacity per 100,000 lbs. per year
From: "James Rakocy"
Date: Tue, 21 Mar 2000 17:16:22 -0400
Ron, You need to contact Dr. Greg Lutz, aquaculture extension specialist, at
LSU. He will give you a comprehensive picture the tilapia operations in
Louisiana and the market picture. The live market is saturated right now
and the economics of producing fillets in the U.S. have never been
competitive with fresh fillet imports. Maybe you could develop niche
markets. Greg knows it all and he will give you very good advice. Jim R.
----- Original Message -----
From: Peter D. Rau
To:
Sent: Tuesday, March 21, 2000 3:42 PM
Subject: market study/business plan was Re: gallon capacity per 100,000 lbs.
per year
> Ron,
>
> I agree and plan to do such. I live in New Orleans and have found that
many
> restaurants and supermarkets are providing Tilapia to their customers.
All of
> the responses to my inquiries result in the same response - pre-frozen,
imported
> (mostly from South America).
>
> There are hundreds of restaurants here that use only fresh fish. Due to
our
> proximity to the Gulf of Mexico, that hasn't been a problem in the past.
Recent
> regulations on some of the fish more commonly used have put many of these
> restaurants in a bind. Based on what I've seen, a percentage of them may
be open
> to trying fresh Tilapia.
>
> I am developing a market survey to determine the overall attitude about
the use
> of Tilapia, about having fresh Tilapia available, and about having
pesticide free
> herbs/vegetables available.
>
> I'd also like to explore the possibilty of providing live Tilapia.
>
> Prawn interest me as well, but I don't know what the market possibilities
are
> since the only restaurants here that serve them are Asian types as sushi.
>
> I have several prospective investors and also am looking into working with
the
> fisheries programs at several local universities for possible work
> study/internship programs.
>
> Regards,
> Peter
>
> > Peter
> > In writing a business plan for a commercial facility prior to
system
> > sizing it may be prudent to conduct a thorough market study. Determine
how
> > much product at what prices can be sold on a regular basis. If you are
> > planning on financing a commercial faciliity then it is important to get
a
> > good handle on this part of the planning process because your lending
> > institution will demand this information. Many growers and
aquaculturists
> > have found themselves in the unenviable position of having market ready
> > product that they cannot unload. Once you have a good idea of what you
can
> > sell then sizing of your facility will be easier and will be based on a
> > good business model.
> > Ron Polka
> > Southwest Technology Development Institute
> > New Mexico State University
> > Box 30001, Dept 3SOL
> > Las Cruces, NM 88003
> > rpolka@nmsu.edu
>
>
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 27 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: market study/business plan
From: "Peter D. Rau"
Date: Tue, 21 Mar 2000 15:29:16 -0600
Jim,
Do you have an email address for Dr. Greg Lutz? I'm the one in New Orleans, not
Ron. Thanks for the contact though. I'll be sure to track him down.
Regards,
Peter
James Rakocy wrote:
> Ron, You need to contact Dr. Greg Lutz, aquaculture extension specialist, at
> LSU. He will give you a comprehensive picture the tilapia operations in
> Louisiana and the market picture. The live market is saturated right now
> and the economics of producing fillets in the U.S. have never been
> competitive with fresh fillet imports. Maybe you could develop niche
> markets. Greg knows it all and he will give you very good advice. Jim R.
>
> ----- Original Message -----
> From: Peter D. Rau
> To:
> Sent: Tuesday, March 21, 2000 3:42 PM
> Subject: market study/business plan was Re: gallon capacity per 100,000 lbs.
> per year
>
> > Ron,
> >
> > I agree and plan to do such. I live in New Orleans and have found that
> many
> > restaurants and supermarkets are providing Tilapia to their customers.
> All of
> > the responses to my inquiries result in the same response - pre-frozen,
> imported
> > (mostly from South America).
> >
> > There are hundreds of restaurants here that use only fresh fish. Due to
> our
> > proximity to the Gulf of Mexico, that hasn't been a problem in the past.
> Recent
> > regulations on some of the fish more commonly used have put many of these
> > restaurants in a bind. Based on what I've seen, a percentage of them may
> be open
> > to trying fresh Tilapia.
> >
> > I am developing a market survey to determine the overall attitude about
> the use
> > of Tilapia, about having fresh Tilapia available, and about having
> pesticide free
> > herbs/vegetables available.
> >
> > I'd also like to explore the possibilty of providing live Tilapia.
> >
> > Prawn interest me as well, but I don't know what the market possibilities
> are
> > since the only restaurants here that serve them are Asian types as sushi.
> >
> > I have several prospective investors and also am looking into working with
> the
> > fisheries programs at several local universities for possible work
> > study/internship programs.
> >
> > Regards,
> > Peter
> >
> > > Peter
> > > In writing a business plan for a commercial facility prior to
> system
> > > sizing it may be prudent to conduct a thorough market study. Determine
> how
> > > much product at what prices can be sold on a regular basis. If you are
> > > planning on financing a commercial faciliity then it is important to get
> a
> > > good handle on this part of the planning process because your lending
> > > institution will demand this information. Many growers and
> aquaculturists
> > > have found themselves in the unenviable position of having market ready
> > > product that they cannot unload. Once you have a good idea of what you
> can
> > > sell then sizing of your facility will be easier and will be based on a
> > > good business model.
> > > Ron Polka
> > > Southwest Technology Development Institute
> > > New Mexico State University
> > > Box 30001, Dept 3SOL
> > > Las Cruces, NM 88003
> > > rpolka@nmsu.edu
> >
> >
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 28 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: market study/business plan
From: "James Rakocy"
Date: Tue, 21 Mar 2000 17:54:50 -0400
The last e-mail I have is lutz@gateway.net
----- Original Message -----
From: Peter D. Rau
To:
Sent: Tuesday, March 21, 2000 5:29 PM
Subject: Re: market study/business plan
> Jim,
>
> Do you have an email address for Dr. Greg Lutz? I'm the one in New
Orleans, not
> Ron. Thanks for the contact though. I'll be sure to track him down.
>
> Regards,
> Peter
>
> James Rakocy wrote:
>
> > Ron, You need to contact Dr. Greg Lutz, aquaculture extension
specialist, at
> > LSU. He will give you a comprehensive picture the tilapia operations in
> > Louisiana and the market picture. The live market is saturated right
now
> > and the economics of producing fillets in the U.S. have never been
> > competitive with fresh fillet imports. Maybe you could develop niche
> > markets. Greg knows it all and he will give you very good advice. Jim
R.
> >
> > ----- Original Message -----
> > From: Peter D. Rau
> > To:
> > Sent: Tuesday, March 21, 2000 3:42 PM
> > Subject: market study/business plan was Re: gallon capacity per 100,000
lbs.
> > per year
> >
> > > Ron,
> > >
> > > I agree and plan to do such. I live in New Orleans and have found
that
> > many
> > > restaurants and supermarkets are providing Tilapia to their customers.
> > All of
> > > the responses to my inquiries result in the same response -
pre-frozen,
> > imported
> > > (mostly from South America).
> > >
> > > There are hundreds of restaurants here that use only fresh fish. Due
to
> > our
> > > proximity to the Gulf of Mexico, that hasn't been a problem in the
past.
> > Recent
> > > regulations on some of the fish more commonly used have put many of
these
> > > restaurants in a bind. Based on what I've seen, a percentage of them
may
> > be open
> > > to trying fresh Tilapia.
> > >
> > > I am developing a market survey to determine the overall attitude
about
> > the use
> > > of Tilapia, about having fresh Tilapia available, and about having
> > pesticide free
> > > herbs/vegetables available.
> > >
> > > I'd also like to explore the possibilty of providing live Tilapia.
> > >
> > > Prawn interest me as well, but I don't know what the market
possibilities
> > are
> > > since the only restaurants here that serve them are Asian types as
sushi.
> > >
> > > I have several prospective investors and also am looking into working
with
> > the
> > > fisheries programs at several local universities for possible work
> > > study/internship programs.
> > >
> > > Regards,
> > > Peter
> > >
> > > > Peter
> > > > In writing a business plan for a commercial facility prior
to
> > system
> > > > sizing it may be prudent to conduct a thorough market study.
Determine
> > how
> > > > much product at what prices can be sold on a regular basis. If you
are
> > > > planning on financing a commercial faciliity then it is important to
get
> > a
> > > > good handle on this part of the planning process because your
lending
> > > > institution will demand this information. Many growers and
> > aquaculturists
> > > > have found themselves in the unenviable position of having market
ready
> > > > product that they cannot unload. Once you have a good idea of what
you
> > can
> > > > sell then sizing of your facility will be easier and will be based
on a
> > > > good business model.
> > > > Ron Polka
> > > > Southwest Technology Development Institute
> > > > New Mexico State University
> > > > Box 30001, Dept 3SOL
> > > > Las Cruces, NM 88003
> > > > rpolka@nmsu.edu
> > >
> > >
>
>
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 29 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: gallon capacity per 100,000 lbs. per year
From: Bertmcl
Date: Tue, 21 Mar 2000 17:37:59 EST
Jim,
What size fingerling do you start with to get your 2 crops per year?
Thanks,
Bert
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 30 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Any suggestions
From: "Barry Thomas"
Date: Tue, 21 Mar 2000 22:51:03 -0000
Sam,
> it's prbably simpler to build cages (or hapas) that will sit
> inside the tank (or float). the problems are usually
> cleaning the tank and getting adequate water flow
> through the cages. the netting itself will also foul after a
> bit.
> sam
As you say, cages come with problems. In addition to these I believe it
would be difficult to make cages that can be easily varied in size
without wasting tank volume.
I suppose that anything you place in the tank will foul over time but
vertical dividers wouldn't have that large a surface area and shouldn't
interfere too much with cleaning?
Barry
barrythomas@btinternet.com
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 31 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: Duckweed Chronicles
From: "TGTX"
Date: Tue, 21 Mar 2000 19:33:07 -0600
SAM SAYS:
> if you come across any reference to boron in your further adventures, i'd
> like to know (in our area we have wasterwater available that
occaissionally
> runs "high" in boron)
>
> sam
Sam, we should acknowledge those who think this is a boron topic, and
then...let's just go ahead and talk about it anyway.
Again, from Volume 1 of the Duckweed Monograph referred to earlier:
"The necessary amount of boron (B) for optimal growth of L. minor and W.
arrhiza is at about the same level as for manganese (0.05 mg/L)"
References:
Steinberg, R.A., 1946 Mineral requirements of Lemna minor. Plant Physiol.
21, 42-48.
Eichhorn M. and Augsten H., 1974, Der Einfluss des Bors auf
verschiedenaltrige Populationen von Wolffia arrhiz (L.) Wimm. in
Chemostaten-Kultur. Biochem. Physiol. Pflanzen 165 (4), 371-385.
"The lower (Boron) limit of good growth is higher for S. polyrrhiza: 1 mg/L
Reference: Eyster, C., 1966: Optimization of the physiological activity
(growth rate) of the giant duckweed, Spirodela polyrhiza. Final Report.
Monsanto Res. Corp. Dayton Lab., Dayton, Ohio. 200 pp.
"The toxic limit for B for S. polyrrhiza is 10mM, for L. minor 5 mM, and for
W. arrhiza somewhat higher than 0.02 mM. The shortage of boron has a
greater effect with nitrate than with ammonium as a nitrogen source...Eyster
1966 raises the question if boron plays some role in the uptake or
assimilation of the nitrate. High light intensities aggrevate the boron
starvtion symptoms, low light intensities moderate them..."
" In clay suspensions, B concentrations of as low as 0.01 mM inhibit growth
of L. minor. However, the toxic effect can be neutralized by addition of
Ca. The highest boron content in the frond (4600 ppm B on a dry weight
basis) was acheived with 1 ppm B (0.1 mM) and relatively high Ca
content.....Bolgiano 1979 reports on a more pronounced toxicity of high
boron concentrations if the Ca concentration is low. Compared with
Ceratophyllum demersum, L. minor takes up much more boron (up to 45 times)
(Glandon and McNabb 1978).
How's that, Samuel?
Shalom!
Ted
.------ ------ ------ ------ ------ ------ ------ ------ ------ ------.
| Message 32 |
'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'
Subject: Re: more duckweed
From: "TGTX"
Date: Tue, 21 Mar 2000 20:59:21 -0600
> > Ted,
> > what do your books have to say about fish feed formulations?
> >
> Tony Cooper.
Tony: Here we go:
Bird food: An advantage of Lemna. for poultry food is the high content of
carotenoids, especially carotene and xanthophyll, which favors the coloring
of fat and skin of the birds. Also the egg yolk is more intensely colored
when the birds are feed with Lemna minor. One hectare of duckweed culture
is sufficient to raise 4000 to 7000 chickens and ducks during a vegetation
period. Rejmankova (1981) calculated an area of 1 hectare Lemna. cover as
sufficient to produce protein for 480 ducks during the warm season.
Fish: Lemna. are a very valuable source of food for many fish. On the
other hand, a closed cover of Lemna. may prevent the supply of oxygen to the
water, thus resulting in unfavorable conditions for fish sensitive to low O2
content. Trout, for example, are not suited for raising in Lemna. ponds.
In cultures with a mix of L. gibba and L. minor, the weight of the fish was
tripled (100 to 300 g per fish) within 50 days. According to Van Dyke and
Sutton (1977) , the grass-carp is able to use 65% of the dry weight of
Lemna. for food: 61% of the gross energy content, 70% of the rough protein,
72% of the organic cell content, 30% of the organic parts of the cell wall.
The food conversion rate on a dry weight basis of grass-carp feeding on
Lemna. amounts to 1.6 for a fish of 3 gram and 2.7 for a fish of 63 gram.
No other foodstuff (catfish chow, rye grass, or a mixture of both) was
nearly as efficient (Shireman et. al. 1978).
Channel catfish was successfully fed with up to 20% Lemna. dry weight.
According to Henderson et. al. 1984, and Heckman et al. 1984, Tilapia grows
rapidly in tanks containing duckweed only.
In eastern Asia, W. globosa has been eatn by man for many generations. The
plants are cultivated in ponds of up to 100m^2 area which are supplemented
by rainwater and shaded by bamboo. No artificial fertilizer is supplied.
Every 3 to 4 days part of the Wolffia cover is harvested and eaten as a
vegetable. The species floweres during the monsoon between August and
October and is then considered not wholesome. Cultiviating of W. globosa in
this way yields 2 tons protein, 4.5 ton carbohydrate, and 0.5 ton fat per
hectare per year. Nakmakura (1960) reports that the taste of Wolffia is
excellent and sweet, resembling that of cabbage.
It is rather astonishing that Lemna. which are so wide-spread have not been
used as human food in other regions. R.A. Alberts 1979 assumes that the
Mayas in Guatemala use Lemna. as foodstuff under the name of Xim Ha ("water
corn"). He thinks that in expansive irrigation systems the Mayas were able
to nourish the numerous people living in a relatively small area with the
productive Lemna.
The explanation that the use of Lemna as a human food is restriced might be
the following:
Lemna and especially Spirodela and Lemna contain a great amount of oxalic
acid, partly in solution and partly crystallized...They are therefore not
very agreeable in taste (rather harsh). Sutton 1981, describes an edible L.
gibba salad, and Ney states that L. minor is far superior in taste to
Chlorella. It is evident that Wolffia and Wolffiella which have the oxalate
in the free form are more suited for food than Spiroldela and Lemna.
HARVEST:
Pure cultures of Lemna are relatively easy to harvest. The fronds can be
skimmed off by some kind of net, or they can be collected at the outlet of
the water by a grid. The highest yield is achieved if the close by not
many-layered Lemna. cover is gathered at short intervals. According to Said
e.al. 1979, and Culley and Myers 1980, the daily harvest is more
advantageous than the weekly harvest (23.3 ton dry weight per hectar vs.
17.6 tons). Rejmankova et al 1983 developed best harvest strategy at 1 to
2 day intervals ( 800 g dry weight /m^2 in 90 days compared with 600 g if
harvested every 14 days). Differently, Ryther, et. al. 1980 and Debusk et.
al. 1981 did not get a higher production if harvested every day compared
with every 5 to 10 days. In northern Thailand, W. globosa is gathered every
3 to 4 days, an interval which proved to be favorable after many years of
experience.
Drying is necessary to store the Lemna. yield. According to Schulz 1962,
Lemna. become dry on a sunny day in Central Europe within 10 hours if turned
over several times. Without the periodic turning over the drying takes much
longer than for making hay, and it is only possible if no rain or strong
wind occurs. The drying of a 5 cm thick layer of S. punctata at 100C takes
about 10 hours . At this temperature, some of the proteins are lost. Also,
Porath and Koton 19877, point out the fact that the content of digestible
proteins and amino acid s is diminished during heat drying. If the water is
pressed out mechanically, a 66-71% los of proteins is recorded by Lawson et
al. 1974.
That's it for tonight.
Happy Duckweeding.
Ted
|
