Aquaponics Digest - Thu 09/16/99




Message   1: Re: ozone generators

             from "Sam Levy" 

Message   2: Re: ozone generators

             from Dave Miller 

Message   3: Re: ozone generators

             from Mike Strates 

Message   4: Re: small family set up

             from Jim Sealy Jr 

Message   5: Re: small family set up

             from Jim Sealy Jr 

Message   6: Re: Pictures/attachments, was Re: Root Crops

             from 

Message   7: Re:       Re:       Re: I want to join your discussion group

             from 

Message   8: Re: Trout dietary needs

             from 

Message   9: Re: small family set up

             from 

Message  10: 

             from 

Message  11: Re: ozone generators

             from Marc & Marcy 

Message  12: Nutrient and water uptake

             from Ronald Polka 

Message  13: Re: Nutrient and water uptake

             from "William Brown" 

Message  14: floating raft tables

             from Adriana Gutierrez & Dennis LaGatta

Message  15: Re: Nutrient and water uptake

             from "William Brown" 

Message  16: Re: ozone generators

             from "Frank Stancato" 

Message  17: Re: floating raft tables

             from "William Brown" 

Message  18: Re: ozone generators

             from Mike Strates 

Message  19: Re: ozone generators

             from "Jewel Lopez" 

Message  20: Re: Nutrient and water uptake

             from "Jewel Lopez" 

Message  21: Re: floating raft tables

             from Adriana Gutierrez & Dennis LaGatta

Message  22: dissolved oxygen DO     Re: ozone generators

             from William Evans 

Message  23: tilapia origin

             from "Wendy Nagurny" 

Message  24: Re: floating raft tables

             from "William Brown" 

Message  25: Re: Pictures/attachments, was Re: Root Crops

             from "Jewel Lopez" 

Message  26: Re:       Re: Trout dietary needs

             from "Jewel Lopez" 

Message  27: Re:       Re: small family set up

             from "Jewel Lopez" 

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| Message 1                                                           |

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Subject: Re: ozone generators

From:    "Sam Levy" 

Date:    Wed, 15 Sep 1999 22:01:04 PDT

jay--

you might want to check out your local safety requirements before 

configuring in an ozone generator.  also consider you configuration 

carefully as adding ozone to culture water is ver similar to pouring in 

bleach in many respects.

sam

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| Message 2                                                           |

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Subject: Re: ozone generators

From:    Dave Miller 

Date:    Thu, 16 Sep 1999 01:04:33 -0400

Sam,

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

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| Message 3                                                           |

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Subject: Re: ozone generators

From:    Mike Strates 

Date:    Thu, 16 Sep 1999 18:50:48 +1000

On Thu, Sep 16, 1999 at 01:04:33AM -0400, Dave Miller wrote:

> 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?

Ozone is a poison. Its the reason why your eyes itch and your sinuses play

up after a thunderstorm. Airborne ozone can cause problems with your lungs,

or even unconciousness in large enough doses. Remember, oxygen is O2 --

ozone is O3... there IS a difference.

-- 

Mike "Skyfox" Strates ; www.croftj.net/~mstrates

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Subject: Re: small family set up

From:    Jim Sealy Jr 

Date:    Thu, 16 Sep 1999 05:52:06 -0500

Mike,

Check with the local auto supply stores who mix paint. Most have changed

over to using digital scales in the last couple of years and you can

probably pick up one of the old shadowgraph scales for little or

nothing. These are accurate to .1 gram and work in the weight range

needed for checking fish growth. I use an Ohaus digital meant for the

same purpose and love it. Just put a bucket of water on the scale, zero

the reading (same as when mixing paint), then add your fish. I also

still have the old shadowgraph I used for about 20 years before that and

there's really not anything to wear out on it. It just doesn't have a

port to hook into the computer for recording weights. This method won't

overly stress the fish and you can weigh even the smallest fry fairly

safely.  Always remember to re-zero the scale between fish if you're

checking several samples, otherwise your fish will get progressively

heavier for some strange reason. ;) Nah, I've never _really_ done that..

Honest!.

At 55 gallons, your tank is just about the perfect size to use an inline

heater intended for maintaining the block temp on an auto engine. These

can also be picked up fairly cheaply at most auto parts stores (and

junkyards), just don't place all your trust in the thermostat on one

from the junkyard. I've used water heater thermostats with good results

over the years.

Can't help much on where to find barley straw, but I've tried wheat

straw and found it works also. I've seen it available as bedding where

horse supplies are sold around here.

Jim Sealy Jr.

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| Message 5                                                           |

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Subject: Re: small family set up

From:    Jim Sealy Jr 

Date:    Thu, 16 Sep 1999 05:58:15 -0500

You'd never guess I was behind on reading the forum, huh? 

Jim Sealy Jr wrote:

> 

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Subject: Re: Pictures/attachments, was Re: Root Crops

From:    

Date:    Thu, 16 Sep 1999 7:47:18 + 5 EST

sounds good here, too!

Mike

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| Message 7                                                           |

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Subject: Re:       Re:       Re: I want to join your discussion group

From:    

Date:    Thu, 16 Sep 1999 7:50:02 + 5 EST

Yeah, that is snow!!!  We average about 120-150 inches per year throughout

the season.

Sources for trout.....  Not much around your neck of the woods i am familiar

with.  We get most of 

ours from the Dept of Environmental Conservation here in NY - they are more

than willing to give us 

a couple hundred every year!

Mike

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| Message 8                                                           |

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Subject: Re: Trout dietary needs

From:    

Date:    Thu, 16 Sep 1999 8:10:55 + 5 EST

Jewel,

Trout are mainly supplied in nature by macroinvertebrates such as stone

flies, small crustaceans, 

and the many insects that hang out in and near water.  (this includes

crickets, g-hoppers, ants, 

etc...)  Larger trout have been known to take small mice, large minnows and

in some cases other 

game fish (yes, including other trout).

In recircultaing aquaculture systems, trout are usually fed a high fat ,

high protein (+/- 40%) trout 

food relative to their mass and overall size.  Most Trout will start on a

small crumble(almost granular 

like coffee and appropriate for fish up to about 3 inches) and then the size

of the food is increased 

to as large as 1/4".  The most entertaining thing is that it seems innate

for them to take earthworms, 

as well.  My students thoroughly dangling a worm over the tank.  Trout have

great vision above 

water, also, and strike the worm and take it right out of the hand of the kids.

Watch what you feed!!! Cheap food is usually just that - CHEAP.  Make sure

you get quality stuff 

(Zeigler, Hikari, etc...).  Cold store your feed and use it up within about

6 months.  DO NOT LET IT 

GET WET (odd, since it gets wet when in use).  You will end up with a 50

pound block of solid food 

if the humidity/water content increases too much.  Also, for clearer water,

consider running it 

thtough a screen sieve to shake out any fine powder.  This can reek havoc

with your bacterial 

colony/biofiltration system.

We feed this food to our tilapia and our trout.  Growth rates increase

dramatically.  I would 

reccommend visiting Aquatic Ecosystems http://www.aquatic-eco.com.  They

have a FANTASTIC 

tech support site and the people there are quite helpful (look for my letter

in the front of the 

catalog, unless they have taken it out - page 2).  

Hope this helps!

Mike

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| Message 9                                                           |

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Subject: Re: small family set up

From:    

Date:    Thu, 16 Sep 1999 8:17:18 + 5 EST

Mike,

You can get Barley straw from "Aquatic EcoSystems" in Apopka, FL (although

they may be shut 

down for Floyd right now.  They have it in stock as well as a great little

"tech-talk" section regarding 

its use.  They sell 1/2 pound for $6.95 - Item #BST5.  They are located at 

http://www.aquatic-eco.com

or

aes@aquaticeco.com

or

1-800-422-3939

Mike

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| Message 10                                                          |

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Subject: 

From:    

Date:    Thu, 16 Sep 1999 10:59:48 + 5 EST

Tilapia Question.....

We are designing a student run experiment on the following - any thoughts?

We have discovered that when we feed sinking food to our tilapia, the feces

that they produce 

seems to float to the surface.  HOWEVER, when we feed floating food, the

feces tends to sink.  Is 

there a correlation that anyone can give us background information on?

Mike

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| Message 11                                                          |

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Subject: Re: ozone generators

From:    Marc & Marcy 

Date:    Thu, 16 Sep 1999 09:11:09 -0600

> Some ozone systems use UV lights (sometimes called

> "blacklights").  You can find the florescent UV tubes all over, I've seen

> them at some walmarts, and you can get a complete 18" unit with fixture from

> those Spencer gift shops that are in most big malls.  It would just be a

> matter of putting it into a little box, then using an aquarium air pump to

> take the air from there, and bring it into the water as usual.

Won't work. Don't waste your money. The "black lights" sold

for decorative purposes are not designed to put out ozone.

The bulbs used to generate ozone are around 50 to 90 dollars

and will damage your eyes if you look at them too long.

Entire units cost well over a thousand dollars for a cheap

one that really works.

I suggest you refer to:

http://www.atlanticuv.com/sterlray/index2.htm

You can note the safety information for ozone on the above

web site.

The water treatment industry in the USA IS NOT REGULATED

WELL SO BUYER BEWARE when it comes to sales claims about

safety. Ozone is a poison no matter what irresponsible ozone

purification vendors claim. It is not as "safe, fresh and

natural as nature". Ozone is as "dangerous, fresh and

natural as any other natural oxidizer". 

Proper ventilation is essential for safety, especially for

home-brew systems where you don't know how much residual

ozone you have.

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Subject: Nutrient and water uptake

From:    Ronald Polka 

Date:    Thu, 16 Sep 1999 10:20:20 -0600

Greetings all

        I am looking for information relating to the water and nutrient uptake

rates for floating raft systems that cultivate bibb type lettuce. What is

most important is the total usage of water and nutrients in the complete

culture cycle. Does anyone know of published papers or other data relating

to this? TIA

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 13                                                          |

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Subject: Re: Nutrient and water uptake

From:    "William Brown" 

Date:    Thu, 16 Sep 1999 08:08:57 -1000

I have 10 floating raft tables in commercial production.  They're great,

easy to work with and I get a 10F lower temperature on hot days compared to

white plastic covered tables.  I put a piece of 1x2 inch lumber on each side

so the raft is suspended when the nutrient solution is consumed.  This

allows to the roots to hang and absorb more oxygen.  I grow leaf lettuce

which I calculate (by experiment) use 1 gallon of water/lettuce upto .66lbs.

I would expect that Bibb lettuce is similar if you adjust for the smaller

size/weight.

For nutrient we assume a lettuce is 95% water.  When dried and analysed the

5% organic matter is approx 3.5% nitrogen.  (per Dr. B A Kratky,

Non-circulating Hydroponic Metthods available at HSA library). We add

nutrient based on the NPK to solution to allow 3.5% nitrogen/plant

So .66lbs = 10.5oz lettuce x 5% dry matter = .525oz dry matter x 3.5%N =

.018oz N/gallon water for each lettuce.  I use a lettuce fertilizer with

8%N.  So 1oz nutrient = .08oz N and .018/.08 = 1/4oz nutrient/gallon water

for each lettuce.  Theoretically you would end up with no leftover water or

fertilizer, alas life is not so perfect.

My experience has been it is better to just keep the pH at 6.2 and the EC at

1.8 (red lettuce should be lower, 1.5EC). I know some people will have

different EC suggestions but for our conditions and setup an EC of 1.8 is

best.

William Brown mahiwai@cmpmail.com

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Subject: floating raft tables

From:    Adriana Gutierrez & Dennis LaGatta 

Date:    Thu, 16 Sep 1999 14:15:09 -0400

William,

Can you tell us a little bit about your tables?  How are they

constructed and how do they operate?  Thanks.

Adriana

> I have 10 floating raft tables in commercial production.

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| Message 15                                                          |

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Subject: Re: Nutrient and water uptake

From:    "William Brown" 

Date:    Thu, 16 Sep 1999 08:23:55 -1000

Forgot to mention that the Knott's Handbook for Vegetable Growers has a

table that lists water content, nitrogen and various other composition

elements for most vegetables.

William Brown mahiwai@cmpmail.com

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| Message 16                                                          |

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Subject: Re: ozone generators

From:    "Frank Stancato" 

Date:    Thu, 16 Sep 1999 15:04:14 -0400

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

current passed through water will produce O2 and H2. I can not for the life

of me remember which terminal produces which gas. If you vent the H2

(exposive) you should have no trouble.

Frank

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Subject: Re: floating raft tables

From:    "William Brown" 

Date:    Thu, 16 Sep 1999 09:27:43 -1000

My raft tables are constructed with 2x4 lumber with dimesions 3x12 feet

which let me put 48 lettuce in each table.  The bottom is used corrugated

roofing nailed to the lumber.  This table is then rested on top of 4x4 inch

lumber installed as supporting legs. Some people build the table legs and

nail the roof iron to the legs and lay the lumber frame on the roof iron.

Each table is lined with 6mil plastic from the hardware store.  Before

laying the plastic I add a 1x2 inch length of lumber along the sides inside,

this holds the rafts up with the some of the roots exposed to the air when

the nutrient solution goes down giving the lettuce more oxygen when they

need it most at maturity and high temps.  I purchase 2x6 foot foam sheets

(made for rafts) from a local distributor which I cut 2 inch holes in spaced

1 foot apart (approx).  I lay these on the plastic covered 1x2s and fill

the table with water.  In the holes I use 2 inch net pots which extend into

the nutrient solution and hold the lettuce.  I place the lettuce seedling

plugs from a 98 cell plastic tray in the net pots without additional media.

Makes cleaning and replanting a quick and painless process.  I like to grow

the seedlings as large as possible, in my case 2-3 weeks depending of the

weather.  At this time the roots bind the Sunshine Mix #5 mixed with coco

fiber together and will pop out of the tray with a careful tug.  In the

summer I will have to add water because of the higher transpiration, but

during winter I generally don't need to adjust anything.  I use nutrient

injectors to combine the nutrient with the water at the time I fill the

tables with water.  Our water is highly acid and I occasionally have to

adjust pH but generally I just let the nutrient buffer the solution.

The floating raft system is significant in reducing solution temperature for

those of us living with high summer temperatures.  I mentioned 10 degrees F.

What I didn't mention is that the plastic covered tables will get temps in

the 90s while the highest the raft tables have been is 81 degrees F.  A

great way to ward off oxygen problems.  I may even add fish again to eat the

mosquito larvae.  In the past the summer heat would kill of the little fish.

I was using guppies.

 I never empty the solution from the table, I just fill them up again.

Contrary to some contemporary notions this setup has been in production for

over seven years and produces extremely fine lettuce.  Occasionally the

nutrient chemistry does get out of wack, usually if I get a pest infestation

or the day/night temps are too high or close to equal and the lettuce

doesn't grow right, then I will empty the table and refill to get things

back in balance and the lettuce will green up. The lettuce will look a

little yellow telling me it's time to fix things up.  It's not unusual to

have a table go 1 to 2 years without being flushed.

If I missed anything get back to me.

William Brown mahiwai@cmpmail.com

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| Message 18                                                          |

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Subject: Re: ozone generators

From:    Mike Strates 

Date:    Fri, 17 Sep 1999 07:48:57 +1000

On Thu, Sep 16, 1999 at 03:04:14PM -0400, Frank Stancato wrote:

> Jay, my understanding about ozone (O3) was that it was used for sanitary

> reasons and not as an oxygen (O2) supplement.

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. It is my personal opinion that O3 is too dangerous

for home aquaculture use.

> Has anyone ever tried using the old chem lab experiment? A low voltage

> current passed through water will produce O2 and H2. I can not for the life

> of me remember which terminal produces which gas. If you vent the H2

> (exposive) you should have no trouble.

What you're talking about is electrolysis. Electrolyzing H2O will indeed

give you H2 and O2, but you forgot one important product -> heat. Because of

this heat, you waste a HUGE amount of energy in making the oxygen, which

you'll never reclaim, even if you burn the hydrogen in an engine. This would

be completely inappropriate for those without access to a several kW free

energy source (ie: most people).

There is hope, however. If you want to supply the fish with pure oxygen, you

could use two systems which can be made at home. To make the first, you'll

need two large water cooler bottles (you know the blue plastic ones).

The idea is that you drill a hole in the caps of the cooler bottles to fit

some cheap garden hose and that you glue the garden hose in with a STRONG

reliable glue. The first cooler bottle needs to be filled around half way

with 30% hydrogen peroxide (this is nasty stuff; be careful...) and mounted

somewhere high... perhaps on a stand of bricks of milk crates or hung from

the roof.

The second cooler bottle sits low and the bottom of the bottle is filled

with around 4lb of maganese dioxide. Drill a hole in the side of the cooler

bottle (ABOVE HALF-WAY, duh! you don't want H2O2 going in the water... so

choose a level which is higher than what the large tank is filled to, get it?)

and glue some airline in.

Cut the hose going from the large bottle to the smaller bottle and insert an

inline regulator tap. Run the airline to the bottom of the aquaculture tank.

Depending on how fast you let the peroxide DRIP into the lower tank, is how

much O2 you'll get. Typically, you'll get 100L of pure O2 gas out of 1L of

30% H2O2 (100 vol, I think.) That's the eqv. of 500L of normal air!

So, what that means is that with 25L of 30% H2O2 (not that expensive) you

can make 2500L of pure O2... that's 12,500L of normal air!!!

The other idea is to use Nitrox gels which are used to fill scuba tanks --

they can increase the O2 content in the air by using a selective membrane.

These need a powerful compressor, though. Comments? -Mike

--

Mike "Skyfox" Strates ; www.croftj.net/~mstrates

Voice: (011) 613-9440-5778; Voicemail (US): 1-888-392-4832, ext: 2913058153

ICQ #47663425

"... and while you're at it, why not treat the pax to some zero

 G's. Just knock the yoke right down the stoppers with one hand,

 and after you've made a perfect recovery, advise all on board

 that this terrible mishap was a result of clear air turbulence"

  -- Mike's 101 Never-Fail Ways to get fired from United.

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| Message 19                                                          |

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Subject: Re: ozone generators

From:    "Jewel Lopez" 

Date:    Thu, 16 Sep 1999 13:53:20 -0600

That's true to an extent, too much concentration of it is a health hazard,

however it does

have many uses in the right amount.  In the air, the right amount makes it

smell like a fresh summer day, too much makes it smell like bleach (which it

is similar to). But like I said earlier, I don't know how it would do with

fish.  It does go away fast though, and we will be using well water that was

previously treated with it, both for drinking and our fish/crops.  We had

one for our boat to kill

mold and other foul "boat odors".  It purifies water.  It actually

eliminates odors rather than masking them.  We used to run it when the kids

had a cold because it kills bacteria and virus' in the air, and it helped

keep the rest of the family from getting it.  Many hotels use units now, to

get rid of odors, including turning a "smoking room" into a "non-smoking

room" in a half hour of running it.  We have a mild 12v cigarette lighter

plug model that we use in the car now for driving in smog, getting rid of

odors, etc.. Again, it is being used for well water

storage tanks to both eliminate fungus, bacteria, algae, etc., and even get

rid of chemical and metal contaminations.  Outside of the US it's even being

used for medical treatments.  You can buy those ozone well water purifiers

from the American Tank Company.

----- Original Message -----

From: Mike Strates 

To: 

Sent: Thursday, September 16, 1999 2:50 AM

Subject: Re: ozone generators

> On Thu, Sep 16, 1999 at 01:04:33AM -0400, Dave Miller wrote:

>

> > 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?

>

> Ozone is a poison. Its the reason why your eyes itch and your sinuses play

> up after a thunderstorm. Airborne ozone can cause problems with your

lungs,

> or even unconciousness in large enough doses. Remember, oxygen is O2 --

> ozone is O3... there IS a difference.

>

> --

>

> Mike "Skyfox" Strates ; www.croftj.net/~mstrates

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| Message 20                                                          |

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Subject: Re: Nutrient and water uptake

From:    "Jewel Lopez" 

Date:    Thu, 16 Sep 1999 13:54:47 -0600

In case this helps at all, I heard of a system like that being used in a

japanese supermarket.

----- Original Message -----

From: William Brown 

To: 

Sent: Thursday, September 16, 1999 12:23 PM

Subject: Re: Nutrient and water uptake

> Forgot to mention that the Knott's Handbook for Vegetable Growers has a

> table that lists water content, nitrogen and various other composition

> elements for most vegetables.

> William Brown mahiwai@cmpmail.com

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| Message 21                                                          |

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Subject: Re: floating raft tables

From:    Adriana Gutierrez & Dennis LaGatta 

Date:    Thu, 16 Sep 1999 17:38:21 -0400

William Brown wrote:

Thanks William,

How deep is your nutrient solution, about 3"?  It appears that your

stryrofoam doesn't actually float on the surface but, rather, sits above

it supported by the 1x2" lumber?

 Before

> laying the plastic I add a 1x2 inch length of lumber along the sides inside,

> this holds the rafts up with the some of the roots exposed to the air 

Do you have a float valve to keep the right level?  I have read that if

you add water above the previous level you would kill the roots.

>   In the

> summer I will have to add water because of the higher transpiration, but

> during winter I generally don't need to adjust anything.  I use nutrient

> injectors to combine the nutrient with the water at the time I fill the

> tables with water.  

You just top up the tables, never dump the old nutrient?

>  I never empty the solution from the table, I just fill them up again.

> have a table go 1 to 2 years without being flushed.

Thanks for sharing.  This confirms the experience of one of our

extension offices.  They set up a float system and the original batch of

nutrient was adequate until harvest.  I've wanted to try this out, it

seems simple enough. 

Adriana

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| Message 22                                                          |

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Subject: dissolved oxygen DO     Re: ozone generators

From:    William Evans 

Date:    Thu, 16 Sep 1999 17:17:21 -0700

 Why make O2 when there's plenty  all around...,  I assume were talking

bout bringing up the DO (O2) content in the water, and not about

sanitation w/ O3. Either a pump system w/ a pressurized discharge onto

the water surface, or some type of mechanical agitator sitting on the

surface,  or other designs that introduce the ambient air into water

circulating in a system.

billevans

Mike> 

> There is hope, however. If you want to supply the fish with pure oxygen, you

> could use two systems which can be made at home. T

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| Message 23                                                          |

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Subject: tilapia origin

From:    "Wendy Nagurny" 

Date:    Thu, 16 Sep 1999 22:43:36 -0400

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

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| Message 24                                                          |

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Subject: Re: floating raft tables

From:    "William Brown" 

Date:    Thu, 16 Sep 1999 17:00:31 -1000

----- Original Message -----

From: Adriana Gutierrez & Dennis LaGatta 

To: 

Sent: Thursday, September 16, 1999 11:38 AM

Subject: Re: floating raft tables

>

> William Brown wrote:

> Thanks William,

>

> How deep is your nutrient solution, about 3"?  It appears that your

> stryrofoam doesn't actually float on the surface but, rather, sits above

> it supported by the 1x2" lumber?

Floats at first until the last 2" of nutrient is used, then roots hang in

the air, just a mod to improve oxygen intake, I know of instances where

floating is all the way down.

>

>  Before

> > laying the plastic I add a 1x2 inch length of lumber along the sides

inside,

> > this holds the rafts up with the some of the roots exposed to the air

>

> Do you have a float valve to keep the right level?  I have read that if

> you add water above the previous level you would kill the roots.

No float valve and haven't killed enough roots to matter.  In fact when I

want to slow growth down for a few days to match market timing I'll overfill

a table without injuring the lettuce.

> >   In the

> > summer I will have to add water because of the higher transpiration, but

> > during winter I generally don't need to adjust anything.  I use nutrient

> > injectors to combine the nutrient with the water at the time I fill the

> > tables with water.

>

> You just top up the tables, never dump the old nutrient?

Correct.

> >  I never empty the solution from the table, I just fill them up again.

> > have a table go 1 to 2 years without being flushed.

>

> Thanks for sharing.  This confirms the experience of one of our

> extension offices.  They set up a float system and the original batch of

> nutrient was adequate until harvest.  I've wanted to try this out, it

> seems simple enough.

There are a few of us here and the Japanese use floating rafts quite

extensively with good effect.

If you want to insure a single original batch of nutrient solution use 6"

high sides instead of 4".  I used 4" originally so I could set containers on

the table bottom, with rafts it lends itself to greater depth.  We found

that the extra depth was useful in keeping the temperature lower since there

is more room for the thermal energy to be absorbed.  I have used 1x4 lumber

a couple times with adequate results, use 2x2 in the corners for secure

attachment of the sides.

>

> Adriana

>

William Brown mahiwai@cmpmail.com

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| Message 25                                                          |

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Subject: Re: Pictures/attachments, was Re: Root Crops

From:    "Jewel Lopez" 

Date:    Thu, 16 Sep 1999 18:59:10 -0600

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?

>

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| Message 26                                                          |

'------ ------ ------ ------ ------ ------ ------ ------ ------ ------'

Subject: Re:       Re: Trout dietary needs

From:    "Jewel Lopez" 

Date:    Thu, 16 Sep 1999 19:06:32 -0600

----- Original Message -----

From: 

To: 

Sent: Thursday, September 16, 1999 2:10 AM

Subject: Re: Trout dietary needs

> as well.  My students thoroughly dangling a worm over the tank.

Thanks Mike.  Do you think the trout could live on earthworms alone?  We are

shooting for as sustainable a system as possible, and growing worms for all

their dietary needs would be great.

Jewel

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| Message 27                                                          |

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Subject: Re:       Re: small family set up

From:    "Jewel Lopez" 

Date:    Thu, 16 Sep 1999 20:38:47 -0600

There's a search engine for farmers that have all kinds of straw/hay.  MUCH

less expensive but you have to catch it at the right time of year.  Now may

still be good.

www.hayexchange.com



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