Aquaponics Digest - Fri 09/17/99
Message 1: Re: ozone generators
from "Sam Levy"
Message 2: Re: ozone generators
from "Sam Levy"
Message 3: Re: ozone generators
from Dave Miller
Message 4: Re: ozone generators
from Marc & Marcy
Message 5: Re: tilapia origin
from Adriana Gutierrez & Dennis LaGatta
Message 6: Re: floating raft tables
from Adriana Gutierrez & Dennis LaGatta
Message 7: RE: ozone generators
from "Stephan de Villiers"
Message 8: Re: ozone generators
from "Sam Levy"
Message 9: Re: Re: Trout dietary needs
from
Message 10: Re: ozone generators
from
Message 11: Re: ozone generators
from "JAY MYERS"
Message 12: RE: ozone generators
from "Stephan de Villiers"
Message 13: Re: tilapia origin
from "JAY MYERS"
Message 14: Re: ozone generators
from "Barry Thomas"
Message 15: PhotoPoint
from S & S Aqua Farm
Message 16: Re: tilapia origin
from "William Brown"
Message 17: Re: floating raft tables
from "William Brown"
Message 18: Re: aphid control
from Rick_Stein-RP5525
Message 19: Re: tilapia origin
from Ronald Polka
Message 20: photo site
from Nelson and Pade
Message 21: RE: Catfish source
from "Ronald W. Brooks"
Message 22: Re: ozone generators
from Mike Strates
Message 23: Nutrient and water uptake
from Ronald Polka
Message 24: unsubscribe
from "Dan Brentlinger"
Message 25: Re: PhotoPoint
from atkindw@cwjamaica.com (david w atkinson)
Message 26: Re: floating raft tables
from "JAY MYERS"
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| Message 1 |
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Subject: Re: ozone generators
From: "Sam Levy"
Date: Thu, 16 Sep 1999 22:08:45 PDT
dave-
ozone is toxic. it is an extremely strong oxidant & can cause great damage
to living tissue--especially that involved in gas exchange (lungs, gills).
my understanding is that some (many ?) states have saftey requirements in
order to protect people from excessive exposure.
i have seen it used in fish culture systems as either a disinfectant for
incoming/recirculated water or in foam fractionation (or both). but care
was always taken to insure a low-zero exposure of both the fish AND the
biofilter (where present) to the ozone.
ozone is three atoms of oxygen bound together (atmosphereic oxygen is two
atoms of oxygen bound together).
>From: Dave Miller
>
>How is the ozone generation dangerous? Somehow I assumed it was
>beneficial. I know oxygen is an accelerant for fire. How are these
>related or different?
>
>recycler dave
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
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| Message 2 |
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Subject: Re: ozone generators
From: "Sam Levy"
Date: Thu, 16 Sep 1999 22:20:04 PDT
mike-
ozone is NOT generally used in a marine set up UNLESS it is operated on
artificial sea water (the bromine in natural sea water combines w/the ozone
and forms hydrobromous acid--(like houshold bleach, just one step down in
family VII)which is a pain to get rid of))
sam
>From: Mike Strates
>Reply-To: aquaponics@townsqr.com
>
>You're completely correct. Ozone is used as a disinfectant, and would be
>useful for cleaning water (possibly in a marine aquaculture setup) but not
>good for anything else.
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| Message 3 |
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Subject: Re: ozone generators
From: Dave Miller
Date: Fri, 17 Sep 1999 01:26:39 -0400
ALL,
I know that ozone is O3 an oxidant and unstable yet it is created during
rainstorms and near waterfalls and gives a sense of fresh air. It also
present all around us. The third "extra" molecule bounces onto other O2
in a continuing pattern.
Yet we sell ozone generators for home use to purify or tone the polluted
air. This is different from ozone associated with the "greenhouse"
effect snd so on.
No? Am I confusing or missing a portion or is there a difference?
dave
--
Nothing is lost when a candle lights another candle.
Light the fire of knowledge.
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Subject: Re: ozone generators
From: Marc & Marcy
Date: Fri, 17 Sep 1999 00:43:41 -0600
..snip..
> Yet we sell ozone generators for home use to purify or tone the polluted
> air. This is different from ozone associated with the "greenhouse"
> effect snd so on.
>
> No? Am I confusing or missing a portion or is there a difference?
..snip..
Same stuff. Ozone is Ozone.
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| Message 5 |
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Subject: Re: tilapia origin
From: Adriana Gutierrez & Dennis LaGatta
Date: Fri, 17 Sep 1999 02:54:53 -0400
Some of it comes from the Middle East, but places like Ecuador and other
countries in Central America are producing lots of tilapia also.
Adriana
> I was wondering (and perhaps it was already mentioned here, but I forgot)
> what country raises the tilapia filets we purchase in our grocers deli?
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Subject: Re: floating raft tables
From: Adriana Gutierrez & Dennis LaGatta
Date: Fri, 17 Sep 1999 03:04:56 -0400
William,
1. Do you aerate the nutrient solution at all?
2. Do you have the raft system in a greenhouse or outside?
3 Is there a good reason to put the rafts on raised tables? Since
water is so heavy it requires substantial support. I would think that by
sinking your troughs into the ground you would get good thermal
insulation. For work purposes you would simply lift the foam sheets out
to a raised surface.
4. Are there lettuce varieties that do better than others in a raft
system? Do things like romaine or radiccio work in it?
Thanks, Adriana
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| Message 7 |
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Subject: RE: ozone generators
From: "Stephan de Villiers"
Date: Fri, 17 Sep 1999 10:48:56 +0200
Hi to all
Remember that Ozone (O3) is a unstable molecule and have a very short life.
It is used in industry to kill bacterial growth and other organic growth
due to the highly oxidising nature of O3. There is companies that use it
to treat water in heat exchanging plants in stead of the normal chemicals
but they have a problem that the life of Ozone is 20 min. if I can remember
correctly.
In some of the Hydroponic books they describe how to make use of ozone to
treat your nutrient mix but I don't know if this will be good for your
fish. Maybe if you can store the treated water for a period of time to
give the Ozone time to breakdown to the O2 molecules.
Stephan de Villiers
-----Original Message-----
From: Marc & Marcy [SMTP:marc@aculink.net]
Sent: 17 September 1999 08:44
To: aquaponics@townsqr.com
Subject: Re: ozone generators
..snip..
> Yet we sell ozone generators for home use to purify or tone the polluted
> air. This is different from ozone associated with the "greenhouse"
> effect snd so on.
>
> No? Am I confusing or missing a portion or is there a difference?
..snip..
Same stuff. Ozone is Ozone.
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| Message 8 |
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Subject: Re: ozone generators
From: "Sam Levy"
Date: Fri, 17 Sep 1999 03:37:01 PDT
dave--
like ammonia, nitrite, co2 & other potentially toxic naturally occuring
substances, it is a question of concetration
sam
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Subject: Re: Re: Trout dietary needs
From:
Date: Fri, 17 Sep 1999 8:01:51 + 5 EST
Jewel,
Could you survive on worms alone?.... My doubts exist on this one. Trout
are very complex and
very picky in their feeding habits (even so much so that light influences
their feeding habits). I
would recommend (and this is by no means the way, truth and light on this
subject) that you try the
food pellets. Although insects and worms, etc. could augment the diet, I
would still be leery of
trying a "worms only" diet.
The trout that you purchase are specific, also. If a trout is raised on
pellets, then that is all they may
know and the worms would go uneaten in many cases. This could lead to
SERIOUS problems in
water quality, detritus matter, etc...
However, if the fish are pond raised and rely on crustaceans,
macroinvertebrates, and
minnows/other fish, you may have some problems. Believe it or not, when we
started at our school
- we just thought that trout were trout. We obtained some pond raised fish
and tried them on
pellets - no dice. A good number of them died before we got them trained to
pellets. It is a double
edged sword. However, after a while they caught on and were a successful
and tasty bunch a year
later!
It is really trial and error and I am most likely not the most qualified
person in this listserv. However, I
am willing to pass along our failures and successes to help you prevent some
common problems!
Mike
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Subject: Re: ozone generators
From:
Date: Fri, 17 Sep 1999 8:07:29 + 5 EST
Frank,
The name of the apparatus that most of us used or at least saw in high
school is a Hoffman
Apparatus. I must admit that I cannot remember which electrode does which,
but it is difficult to
regulate the voltage and could prove fatal for fish and humans - all the h2
and the o2 in the world
isnt worth blowing yourself up. Agitation can provide all the oxygen you
need. We have used a
shower head for beatintg the water into the tank - cheap, effective, and safe.
Mike
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Subject: Re: ozone generators
From: "JAY MYERS"
Date: Fri, 17 Sep 1999 07:22:31 -0500
Frank -
Thanks for your input. I'm an old nuclear submarine sailor and that's the
way we make oxygen for the crew to breathe, so the boats can stay submerged
indefinitely (til we ran out of food - then the crew got a little grumpy !).
Vented the nitrogen out to the sea around, and kept the O2.
My dilemma is to keep the Tilapia happy but keeping their water warm, which
reduces the ability of the water to hold O2, and yet keep the O2 near
saturation to promote growth. Life is full of challenges !
In the big places like Sea World, etc. they use ozone the disinfect, then
inject it to crank the O2 level up. We have a park like that here, and I'm
beginning to learn from their system. If anything useful comes from this
I'll pass it along.
Thanks
Jay
Subject: Re: ozone generators
>Jay, my understanding about ozone (O3) was that it was used for sanitary
>reasons and not as an oxygen (O2) supplement.
>
>Has anyone ever tried using the old chem lab experiment? A low voltage
>curren
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| Message 12 |
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Subject: RE: ozone generators
From: "Stephan de Villiers"
Date: Fri, 17 Sep 1999 14:25:25 +0200
Hi Again
For a bit more info on Ozone try
http://www.hessmachine.com/html/how.html
Stephan
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Subject: Re: tilapia origin
From: "JAY MYERS"
Date: Fri, 17 Sep 1999 08:03:20 -0500
The box in Wal Mart says Indonesia.
-----Original Message-----
From: Wendy Nagurny
To: Aquaponics
Date: Thursday, September 16, 1999 9:41 PM
Subject: tilapia origin
>I was wondering (and perhaps it was already mentioned here, but I forgot)
>what country raises the tilapia filets we purchase in our grocers deli?
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| Message 14 |
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Subject: Re: ozone generators
From: "Barry Thomas"
Date: Fri, 17 Sep 1999 17:02:45 +0100
> My dilemma is to keep the Tilapia happy but keeping their water warm,
which
> reduces the ability of the water to hold O2, and yet keep the O2 near
> saturation to promote growth. Life is full of challenges !
If electrolysis were used to generate O2 & H2, the O2 might be diffused
into a (closed to the atmosphere) tank inserted into your return line
close to fish tank. The excess O2 collected and burnt with H2 which has
not been allowed to collect _anywhere_.
So you get heat from electrolysis plus oxygenation plus more heat from
the burner - might be worth it if it's cold and you've some power
available? Whether it would actually be worth it I don't know.
Just an idea.
Barry
barrythomas@btinternet.co
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Subject: PhotoPoint
From: S & S Aqua Farm
Date: Fri, 17 Sep 1999 11:13:33 -0500
At 06:59 PM 09/16/1999 -0600, Jewel wrote:
>Paula, that makes perfect sense to use your website for that project. Do
>you want everyone to start sending their info and pics to you?
The more I thought about this, the more I was convinced that our site was
inappropriate - not that we wouldn't like to have photos there from all the
various types of systems, but because it's primarily a commercial site and
some folks might be hesitant to place their system pictures there.
There is a free photo-hosting site - PhotoPoint - that's been used and
recommended by members of another list. The explanation/introduction page is:
http://www.photopoint.com/intro.html
I think this would be an ideal spot for those without their own web sites to
post pictures for display, and especially for discussion of topics that
would benefit from "seeing" the actual set-up. I believe you can use this
site with either a scanned picture or digital camera. Then all you need to
do is post the URL to the group.
Eventually we'd like to add links, or a directory of links in a summary page
for the group. Let me know what your opinions are.
Paula
S&S Aqua Farm, 8386 County Road 8820, West Plains, MO 65775 417-256-5124
Web page http://www.townsqr.com/snsaqua/
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Subject: Re: tilapia origin
From: "William Brown"
Date: Thu, 16 Sep 1999 17:09:48 -1000
I'm not saying it comes from Hawaii, but it is naturalized in the local
streams.
William Brown mahiwai@cmpmail.com
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Subject: Re: floating raft tables
From: "William Brown"
Date: Fri, 17 Sep 1999 06:51:22 -1000
William Brown mahiwai@cmpmail.com
----- Original Message -----
From: Adriana Gutierrez & Dennis LaGatta
To:
Sent: Thursday, September 16, 1999 9:04 PM
Subject: Re: floating raft tables
> William,
>
> 1. Do you aerate the nutrient solution at all?
Only by mosquito larva, really no
>
> 2. Do you have the raft system in a greenhouse or outside?
Inside a greenhouse, we get 150" rain avg each year
>
> 3 Is there a good reason to put the rafts on raised tables? Since
> water is so heavy it requires substantial support. I would think that by
> sinking your troughs into the ground you would get good thermal
> insulation. For work purposes you would simply lift the foam sheets out
> to a raised surface.
Convenience, it is so much easier to work on raised tables. We haven't had
any example of tables falling down using 2x4 or 4x4 lumber. Some people
have used concrete blocks. There's no ground here, we live on lava flows
which we break apart for planting and drainage. Which makes hydroponics so
handy here, no soil.
>
> 4. Are there lettuce varieties that do better than others in a raft
> system? Do things like romaine or radiccio work in it?
Haven't tried Romaine yet with the rafts, but it does well in the tables
with pots. I have had limited success with Raddichio which I ascribe to
other cultural practices. Most anything grown in NFT or Aero will grow well
in a raft system if setup properly.
>
> Thanks, Adriana
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Subject: Re: aphid control
From: Rick_Stein-RP5525
Date: Fri, 17 Sep 1999 10:08:05 -0700 (MST)
I've got a white fly problem and was wondering if molasses will work to
rid them as well as aphids ? Also, I haven't found "black strap molasses",
only a sulpher or non-sulpher type. Which shouls I try ?
Thanks Rick
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Subject: Re: tilapia origin
From: Ronald Polka
Date: Fri, 17 Sep 1999 11:29:00 -0600
At 10:43 PM 9/16/1999 -0400, you wrote:
>I was wondering (and perhaps it was already mentioned here, but I forgot)
>what country raises the tilapia filets we purchase in our grocers deli?
>Since tilapia culture is restricted or tightly regulated in most states, I
>presume that the bulk of what is available now in the US, is imported. From
>where?
>Wendy
>
Wendy
Attached is an excerpt from the 1999 USDA Aquaculture Oultlook Report
relating to Tilapia. It may answer some of the questions you have relating
to imports. The following is copied from the report. If you want a copy of
the entire report I can send it as an attachment.
AQUACULTURE OUTLOOK March 05, 1999
March 1999, ERS-LDP-AQS-09
Approved by the World Agricultural Outlook Board
---------------------------------------------------------------------------
AQUACULTURE OUTLOOK, is published twice a year by the Economic Research
Service, U.S. Department of Agriculture, Washington, DC 20036-5831.
Tilapia Imports Forecast Higher in 1999
U.S. tilapia imports are forecast to continue growing in 1999.
However, the rate of increase is expected to be lower than in
previous years. Although the U.S. dollar remains strong against
the currencies of exporters such as Thailand and Indonesia, if
tilapia imports are to continue growing, its marketers will need
to follow the salmon and catfish industries lead and gain greater
widespread acceptance and visibility to increase tilapia product
sales, now ranging from 60 to 70 million pounds, to hundreds of
millions of pounds. The changing demographics of the United
States should allow for continued moderate growth as the
traditional target markets, Asian markets and restaurants,
expand in size. However, importers or producers will aim at
expanding the consumer base to wider markets outside of major
urban areas. Taiwan is expected to remain the dominant tilapia
supplier, but imports of fresh fillets, mainly from Central or
South American countries, are expected to increase as sales
expand to restaurant chains. Because many of these countries are
also farmed-shrimp producers, producers and wholesalers in those
countries have, and are building upon, the resources needed to
expand tilapia production.
Tilapia imports increased to 61 million pounds of product weight
in 1998, 14 percent higher than the previous year. Although
imports of filleted products expanded, tilapia imports grew
primarily because of higher shipments of frozen whole fish from
Taiwan. If tilapia follows a path similar to those of other fish
species, then filleted products are expected to comprise a
larger share of future imports as producers try lowering shipping
costs and increasing earnings through value-added processing.
Taiwan, with almost 80 percent of the total supply on a quantity
basis, continues to be the largest supplier of tilapia. Other
major suppliers are Thailand, Indonesia, Costa Rica, and Jamaica.
The total value of tilapia imports in 1998 incr |
