Aquaponics Digest - Tue 01/18/00
Message 1: Re: Has anyone tried Azolla ( mosquito plant)
from "KevinLReed"
Message 2: Re: Has anyone tried Azolla ( mosquito plant)
from "D.Bennett"
Message 3: Duckweed,Snails and Carbs
from "KevinLReed"
Message 4: Re: Has anyone tried Azolla ( mosquito plant)
from "KevinLReed"
Message 5: Re: Has anyone tried Azolla ( mosquito plant)
from Marc & Marcy
Message 6: Re: Has anyone tried Azolla ( mosquito plant)
from "KevinLReed"
Message 7: Re: Has anyone tried Azolla ( mosquito plant)
from Marc & Marcy
Message 8: RE: seedling temperature shock
from "William Brown"
Message 9: Re: seedling temperature shock
from "James Rakocy"
Message 10: Re: Has anyone tried Azolla ( mosquito plant)
from Marc & Marcy
Message 11: profitable Azolla or Duckweed
from "KevinLReed"
Message 12: Re: profitable Azolla or Duckweed
from Marc & Marcy
Message 13: Re: Has anyone tried Azolla ( mosquito plant)
from Bagelhole1
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Subject: Re: Has anyone tried Azolla ( mosquito plant)
From: "KevinLReed"
Date: Mon, 17 Jan 2000 20:06:36 -1000
So far no one has answered so maybe none have used Azolla as a fish food.
Azolla is a floating water plant of the fern family that is a nitrogen fixer
with a protein content of about 23%. Duckweed protein content can be varied
by nutrient control up to 40% protein and so with a good nutrient source
duckweed is the ideal fish food and without a good nutrient source Azolla
might work well.
Kevin
----- Original Message -----
From: "D.Bennett"
To:
Sent: Monday, January 17, 2000 4:30 PM
Subject: Re: Has anyone tried Azolla ( mosquito plant)
> >Has anyone tried Azolla as a fish feed?
> >
> Did anyone answer this? I'm interested in knowing also.
>
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Subject: Re: Has anyone tried Azolla ( mosquito plant)
From: "D.Bennett"
Date: Tue, 18 Jan 2000 01:06:28 -0500
Where can one get duckweed or azolla plants to start?
-----Original Message-----
From: KevinLReed
To: aquaponics@townsqr.com
Date: Tuesday, January 18, 2000 1:06 AM
Subject: Re: Has anyone tried Azolla ( mosquito plant)
>So far no one has answered so maybe none have used Azolla as a fish food.
>Azolla is a floating water plant of the fern family that is a nitrogen
fixer
>with a protein content of about 23%. Duckweed protein content can be varied
>by nutrient control up to 40% protein and so with a good nutrient source
>duckweed is the ideal fish food and without a good nutrient source Azolla
>might work well.
>Kevin
>----- Original Message -----
>From: "D.Bennett"
>To:
>Sent: Monday, January 17, 2000 4:30 PM
>Subject: Re: Has anyone tried Azolla ( mosquito plant)
>
>
>> >Has anyone tried Azolla as a fish feed?
>> >
>> Did anyone answer this? I'm interested in knowing also.
>>
>
>
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Subject: Duckweed,Snails and Carbs
From: "KevinLReed"
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
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Subject: Re: Has anyone tried Azolla ( mosquito plant)
From: "KevinLReed"
Date: Mon, 17 Jan 2000 20:28:23 -1000
> Where can one get duckweed or Azolla plants to start?
Duckweed and Azolla seem to be ubiquitous. Check with your local agriculture
station to find some. A local variety will most likely be better acclimated.
Kevin
----- Original Message -----
From: "D.Bennett"
To:
Sent: Monday, January 17, 2000 8:06 PM
Subject: Re: Has anyone tried Azolla ( mosquito plant)
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Subject: Re: Has anyone tried Azolla ( mosquito plant)
From: Marc & Marcy
Date: Mon, 17 Jan 2000 23:31:26 -0700
KevinLReed wrote:
>
> So far no one has answered so maybe none have used Azolla as a fish food.
> Azolla is a floating water plant of the fern family that is a nitrogen fixer
> with a protein content of about 23%. Duckweed protein content can be varied
> by nutrient control up to 40% protein and so with a good nutrient source
> duckweed is the ideal fish food and without a good nutrient source Azolla
> might work well.
> Kevin
If I follow you correctly:
With commercial strength nutrient levels we get a rompin'
stompin' duckweed.
Aquaponics does not have high levels of nutrients so
duckweed may not be the best choice to grow for fish food
since is is not known for a nitrogen-fixing ability.
Nitrogen-fixin being plant growth utilizing other than
nutrient solution nitrogen.
>From the web site
http://www.fpce.ul.pt/%7Efcarrap/Azolla_e.html we find about
azolla:
The plant has leaves with two lobes. In the dorsal lobe
there is an ovoid cavity which contains a endosymbiotic
community. This community is composed of two types of
prokaryotic organisms: one species of nitrogen-fixing
filamentous cyanobacteria - Anabaena azollae Strasb and a
variety of bacteria that some are identified as
Arthrobacter sp. and associated with other showing the
presence of nitrogenase. As a consequence of this
association, in some regions of the globe (Africa and Asia),
Azolla is used as a nitrogen biofertilizer, namely in rice
fields.
In other words Azolla can find nitrogen and make more Azolla
even if the nutrient solution is low in it.
So if the nutrient is a bit weak Azolla can still do the
trick to generate fish food. If the fish will eat it that
is.
According to this web site fish eat it:
http://www.ias.unu.edu/vfellow/foo/ibs/azolla.htm
Sounds extraordinarily cool Kevin.
Marc S. Nameth
AquaTek Water Services, LLC, 5856 Rd HH.5, Fowler, CO 81039
719 263 5492
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Subject: Re: Has anyone tried Azolla ( mosquito plant)
From: "KevinLReed"
Date: Mon, 17 Jan 2000 20:45:48 -1000
We have lots of pig and cow manure to play with so I am going with the
Duckweed but the tilapia do like both Duckweed and Azolla. If fish feed is
40% to 70% of the on going cost of raising fish ... what is the best you can
do with free organic fish food?
Kevin
----- Original Message -----
From: "Marc & Marcy"
To:
Sent: Monday, January 17, 2000 8:31 PM
Subject: Re: Has anyone tried Azolla ( mosquito plant)
> KevinLReed wrote:
> >
> > So far no one has answered so maybe none have used Azolla as a fish
food.
> > Azolla is a floating water plant of the fern family that is a nitrogen
fixer
> > with a protein content of about 23%. Duckweed protein content can be
varied
> > by nutrient control up to 40% protein and so with a good nutrient source
> > duckweed is the ideal fish food and without a good nutrient source
Azolla
> > might work well.
> > Kevin
>
> If I follow you correctly:
>
> With commercial strength nutrient levels we get a rompin'
> stompin' duckweed.
>
> Aquaponics does not have high levels of nutrients so
> duckweed may not be the best choice to grow for fish food
> since is is not known for a nitrogen-fixing ability.
> Nitrogen-fixin being plant growth utilizing other than
> nutrient solution nitrogen.
>
> >From the web site
> http://www.fpce.ul.pt/%7Efcarrap/Azolla_e.html we find about
> azolla:
>
> The plant has leaves with two lobes. In the dorsal lobe
> there is an ovoid cavity which contains a endosymbiotic
> community. This community is composed of two types of
> prokaryotic organisms: one species of nitrogen-fixing
> filamentous cyanobacteria - Anabaena azollae Strasb and a
> variety of bacteria that some are identified as
> Arthrobacter sp. and associated with other showing the
> presence of nitrogenase. As a consequence of this
> association, in some regions of the globe (Africa and Asia),
> Azolla is used as a nitrogen biofertilizer, namely in rice
> fields.
>
> In other words Azolla can find nitrogen and make more Azolla
> even if the nutrient solution is low in it.
>
> So if the nutrient is a bit weak Azolla can still do the
> trick to generate fish food. If the fish will eat it that
> is.
>
> According to this web site fish eat it:
>
> http://www.ias.unu.edu/vfellow/foo/ibs/azolla.htm
>
> Sounds extraordinarily cool Kevin.
>
> Marc S. Nameth
> AquaTek Water Services, LLC, 5856 Rd HH.5, Fowler, CO 81039
> 719 263 5492
>
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Subject: Re: Has anyone tried Azolla ( mosquito plant)
From: Marc & Marcy
Date: Mon, 17 Jan 2000 23:50:16 -0700
KevinLReed wrote:
>
> We have lots of pig and cow manure to play with so I am going with the
> Duckweed but the tilapia do like both Duckweed and Azolla. If fish feed is
> 40% to 70% of the on going cost of raising fish ... what is the best you can
> do with free organic fish food?
> Kevin
..snip..
Depends on how much they'll actually consume as part of
their diet.
I have done little research on this stuff. Cows will eat
good or bad hay depending on hunger levels with
corresponding growth variations.
It would be interesting to see what type of Azolla and
Purina ratio (or whatever) in terms of profitability.
Have there been any threads on this. Has convergence plots
in terms of ratio/profit, ratio/growth rate, etc. been
published?
G'nite matey,
Marc
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Subject: RE: seedling temperature shock
From: "William Brown"
Date: Tue, 18 Jan 2000 07:06:12 -1000
I too use net pots with rafts. Haven't thought of that question. Are you
using the short 2 inch pots, about 2 inches deep? (I have seen 3 inch deep
too.) If your using the short pot, you don't need to add any media, just
insert the plug directly so they have at least a 1/4 inch of water.
Otherwise there isn't much you can do about the temp. 2 week old plants are
very robust and should adapt easily. I like to transplant in the evening
when the temp differential should be lowest between the plugs and the water.
If you water them just before transplanting you will help lower the plug
temperature and allow the seedlings a greater time to adjust to the
transplanting. There will always be some shock anyway, moving the plugs
from their confined area to the larger pot/tank area (use a plastic knife to
loosen the plugs if they don't come out easily, the biggest source of shock
is ripping off the roots). The roots will sink to the bottom because of
gravity. And all your temps are in a favorable range. Watch out for
Botrytis and let me know how the Romaine do. I would like to get back into
growing romaine for restaurants but wondered if the raft/net pots where
suitable for the size of romaine.
William Brown mahiwai@cmpmail.com
-----Original Message-----
From: aquaponics
[mailto:aquaponics]On Behalf Of Marc Laberge
Sent: Monday, January 17, 2000 6:57 AM
To: aqua
Subject: seedling temperature shock
I need advice on transplanting my seedlings;the seedlings are romaine
lettuce, they will be transplanted once they reach 2 inches. The problem is
, they will be places on a raft system in net pots. The net pots are filled
with clay gravel at the bottom covered by 1 inch of tiny aquarium gravel.
The surface temperature of the gravel is ~18C ( 68F) and the water below is
at 15C ( 60F ).
Question 1. Will this change in temperature greatly shock the plant and
stunt it's growth ? ( The seedlings are in 25C ( 78F ) unit )
Question 2. Is the stratification in the net pot enough to affect the growth
of the roots; will the roots still grow down in search of more nutrients
although the water temperature is colder or will they hang around the warmer
top layer until all nutrients are used up then go down in search of a better
environment ?
Thank You all again for all the advice
Marc Laberge
Mont Tremblant
Qc, Canada
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Subject: Re: seedling temperature shock
From: "James Rakocy"
Date: Tue, 18 Jan 2000 14:26:33 -0400
----- Original Message -----
From: William Brown
To:
Sent: Tuesday, January 18, 2000 1:06 PM
Subject: RE: seedling temperature shock
Net pots and raft culture works fine for romaine during our cooler season
Dec.-April 15. They need more space and time to develop fully, but in 5
weeks of growout we once produced 1.9-lb heads. After mid-April they become
stressed. We were able to produce a variety called Jericho through the hot
season, but we can not find this variety anymore. It came from Israel. Jim
R.
Watch out for
> Botrytis and let me know how the Romaine do. I would like to get back
into
> growing romaine for restaurants but wondered if the raft/net pots where
> suitable for the size of romaine.
>
> William Brown mahiwai@cmpmail.com
>
> -----Original Message-----
> From: aquaponics
> [mailto:aquaponics]On Behalf Of Marc Laberge
> Sent: Monday, January 17, 2000 6:57 AM
> To: aqua
> Subject: seedling temperature shock
>
>
> I need advice on transplanting my seedlings;the seedlings are romaine
> lettuce, they will be transplanted once they reach 2 inches. The problem
is
> , they will be places on a raft system in net pots. The net pots are
filled
> with clay gravel at the bottom covered by 1 inch of tiny aquarium gravel.
> The surface temperature of the gravel is ~18C ( 68F) and the water below
is
> at 15C ( 60F ).
>
> Question 1. Will this change in temperature greatly shock the plant and
> stunt it's growth ? ( The seedlings are in 25C ( 78F ) unit )
>
> Question 2. Is the stratification in the net pot enough to affect the
growth
> of the roots; will the roots still grow down in search of more nutrients
> although the water temperature is colder or will they hang around the
warmer
> top layer until all nutrients are used up then go down in search of a
better
> environment ?
>
>
> Thank You all again for all the advice
> Marc Laberge
> Mont Tremblant
> Qc, Canada
>
>
>
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Subject: Re: Has anyone tried Azolla ( mosquito plant)
From: Marc & Marcy
Date: Tue, 18 Jan 2000 11:51:08 -0700
KevinLReed wrote:
>
> We have lots of pig and cow manure to play with so I am going with the
> Duckweed but the tilapia do like both Duckweed and Azolla. If fish feed is
> 40% to 70% of the on going cost of raising fish ... what is the best you can
> do with free organic fish food?
> Kevin
Since a lot of political steam is vented about nitrates from
animal waste lagoons this could be a major part of an
answer. Would mad cow/pig/chicken disease (prions) be a
factor? What about salinity reduction, another major
concern? Are there plants that do salt or chloride
reduction/conversion.
Back to Azolla.
What I am wondering about is the effect on the nutrient
level available to my growing beds when Azolla is having
part of it's meal in the communal soup pot.
Since I use fish to make available some nutrients for the
growing beds and valuable aquatic plants AND that the
veggies are worth more than the fish the Azolla appears to
be in competition with the growing beds. If the situation
was reversed the growing bed size could be reduced or
actually eliminated it seems. I really don't know.
Can the plant live and grow and not be in competition with
the growing bed flora?
In another abstract the ability of an Azolla form to
facilitate iron for other plants use was mentioned.
http://www.dekker.com/e/p.pl/0190-4167/021/011/008/abs?frame=main&
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
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Subject: profitable Azolla or Duckweed
From: "KevinLReed"
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
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Subject: Re: profitable Azolla or Duckweed
From: Marc & Marcy
Date: Tue, 18 Jan 2000 14:49:37 -0700
> 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
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Subject: Re: Has anyone tried Azolla ( mosquito plant)
From: Bagelhole1
Date: Tue, 18 Jan 2000 21:57:24 EST
I just learned today that what is floating and multiplying so fast is azolla,
I thought it was duckweed. I added a little duckweed today. Do you think the
catfish eat this? There is algae on the plastic sides, maybe they eat that.
The water is pretty clear. But the algae gets pumped up to the vegetable and
could be clogging things up a little, possibly covering the "exploded clay
balls" where the roots lodge and making my plants unhappy. Its hard to tell.
Fishidiot,
Tom O
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