Aquaponics Digest - Sun 06/06/99




Message   1: Re: expanded clay

             from MUDDTOO

Message   2: Re: price - swiss chard

             from Adriana Gutierrez & Dennis LaGatta

Message   3: Ken's Progress Report + Shiso

             from Adriana Gutierrez & Dennis LaGatta

Message   4: Aquaponics - Thoughts on Water Exchange

             from "TGTX" 

Message   5: Re: live transport

             from "vpage" 

Message   6: Re: price - swiss chard

             from STUNTTMAN

Message   7: Re: Ken's Progress Report + Shiso

             from "William Brown" 

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| Message 1                                                           |

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Subject: Re: expanded clay

From:    MUDDTOO

Date:    Sun, 6 Jun 1999 02:36:52 EDT

I'm sure it'd work good, along with perlite which is very lite.  The finer 

the media the more you'd need to pre-filter the sediment out to avoid 

clogging the bacteria bed and causing dead spots.  The reason people buy the 

gravel is because you can get a truck load for what you'd pay for a trunk 

full of perlite, or for a couple bags of expanded clay.  Also be careful with 

the expanded clay - some types (like some for orchids) are not stable and may 

make it very hard to maintain control of the pH.  Both gravel and perlite 

won't add anything to nor take away anything from your system.

joel

In a message dated 6/5/99 6:12:01 PM Pacific Daylight Time, 

Princeb2@pacbell.net writes:

<< Does anyone have experience using expanded clay as a growing media for

 aquaponics.  Similar to what is used for hydroponics.  Looking for a lighter

 media that will work as well as gravel and still house the bacteria. >>

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Subject: Re: price - swiss chard

From:    Adriana Gutierrez & Dennis LaGatta 

Date:    Sun, 06 Jun 1999 04:19:57 -0400

Thanks Stunttman,

  What does that work out to per pound?

Adriana

> I sell green chard for .69$ for a bunch of 6 or 7 large leaves.Red chard for

> .99$ for same amount.

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Subject: Ken's Progress Report + Shiso

From:    Adriana Gutierrez & Dennis LaGatta 

Date:    Sun, 06 Jun 1999 04:29:49 -0400

It's good to hear from you Ken, I was worried when you dropped off the

screen.  When you've sold your 3 grandkids I have 3 kids I can send to

you on consignment beginning Monday.

Are you growing all of those varieties aquaponically?  I noticed you

also have coleus.  In my never-ending quest for red varieties for my

mesclun I grew a trial packet of red perilla seeds, also known as Shiso

which is from the coleus family.  The plants are beautiful, looking like

Red Ruffles Basil but with larger leaves.  Unfortunately to me it tastes

like a chinch bug smells.  My research on the web says it is one of

those herbs that you either love or hate.  The seed catalogs bill it as

a cinnamon flavor.  Not!  Because it is so attractive and is growing

well I would still like to see if I can market some, perhaps for plate

garnish since 3 leaves cover the bottom of a plate.  Is anybody selling

perilla?  Do you have any wisdom you can share here?  I understand that

in Japan it is used for suhi (green varieties) and for pickling and the

flowers are also used for condiments.

Adriana

plant sales picking up,selling Coleus,Pink

> >select,Hoestes,Mexican Heather,Begonias,Dusty Millers,growing some Weeping

> >Willows,Boston Ferns,Peace

> >Plants,Cactus,Azaleas,Palms,Cedars,Caladiums,Lilys,Iris's,Varigated

> >Hosta's,Varigeted Liriope,Celosia,Kudzu and three grandkids,

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| Message 4                                                           |

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Subject: Aquaponics - Thoughts on Water Exchange

From:    "TGTX" 

Date:    Sun, 6 Jun 1999 09:01:10 -0500

Hi folks.

Ken, good to hear about the aquaponic jungle you have going.

Sounds like you have plent of yard apes around to occupy the jungle.

I have been thinking about the topic of aquaponic discharge water for a

while, and I think it is time to compose this proposal or perspective for

you all to consider.

I am reading the National Symposium on Management of Agriculture and

Aquaculture Wastes from 1991 that our fellow participant, Jim Rakocy

contributed to, and had some thoughts to share with you all.

We know that aquaponic systems require some replacement water occasionally,

whether it is due to evaporative losses, or a build up of total dissolved

salts, or a build up of refractory sludge solids (refractory referring to

that remaining fraction of the fish feed and waste material which is mostly

cellulose and lignins and which takes longer to decompose than the other

components).

The timing or frequency of that exchange rate is dependent upon a number of

design and operation factors, such as the fish density which will dictate

the total cumulative feed burden into the closed (recirculating) water

volume over time...Frequency of water exchange will also be affected by the

ratio of plant growing area and thus plant biomass to the fish biomass...the

plant biomass which is rapidly growing will remove a substantial amount of

the nutrients as well as some of the dissolved salts to a degree...as the

plant biomass is harvested, the nutrients that began as fish feed as an

input is exported from the system as salad greens, herbs, tree saplings, or

any number of the plants Ken has in his aquaponic jungle.

I have been in continuous fish culture in my latest aquaponic system for a

little over a year now.  I have not had to exchange the water due to

dissolved salts accumlation yet.

I replace evaporated or leaked water with rainwater occassionally, or with

some potable water which is pretty hard - high in calcium and magnesium

carbonate.  I have been able to raise a fairly high density of tilapia in th

is system without exchanging the water so far, and I have raised salad

greens and basil in this system with the fish culture water under a

continuous operation of daily harvesting- usually Monday through Friday, and

partly on Saturday, (and sometimes Sunday I am sorry to have to say.)

I want to emphasize that, just as the nutrients are being "imported" on a

daily basis in the form of fish feed, we expect that an aquaponics system

will "export" much of the original nutrients and to a degree some of the

dissolved salts out of the water on a steady stream basis..if not daily as I

do, then at least weekly, and if longer than that, it would likely be

because of the kind of plant which is being grown, which is storing the

nutrients and other elements in its biomass until the harvest or transplant

to the outside world takes place..thus, in any case, whether harvested

daily, weekly, monthly, or seasonally, the plant biomass is assimilating the

nutrients and other elements from the fish water and locking up the

nutrients in the plant biomass.  I call this nutrient stabilization.  This

is an fundamental concept and ideal of organic agriculture

I want to emphasize that this nutrient stabilization process is an

instantaneous one, and it involves not only the plants assimilating

nitrogen, for example, but the bacteria on the biofilm of the growing beds

breaking down some of the organic carbon in a very rapid "aquatic composting

process".... except that, instead of huge mounds of manure and straw and

grass clippings in a bulky pile that starts out uncomposted...and subject to

rainwater and leaching into rivers and streams, etc.... and then 2 to 6

weeks later this terrestrial animal agriculture waste is somewhat

decomposed.....by contrast, in an aquaponics system,  the nutrient

stabilization process and waste decomposition....sort of streams in real

time if you like that techno-analogy...in other words, it starts decomposing

the smaller amounts of waste the moment it leaves the animal's body...and

because fish feces have such a higher surface area to volume ratio than does

a "cow paddy" or "field Frisbee", if you will excuse the Texas crude, we

expect to have and in fact observe and experience much more rapid

decomposition once the fine particles collect on the growing bed media such

as perlite or gravel.  - There is a limit to this organic particle capture

process, which we must manage if we are to avoid sludge build up in our

growing beds, but I think we have discussed that before, and many of you are

aware that it takes some fine tuning to avoid that from developing.  Some

choose to go through an extensive solids removal step prior to pumping to

the grow beds, others choose to manage the solids in the fish tank and

gravel by sending it to the gravel and letting the decompostion take place

there.

This is process I have just compared and contrasted is quite different from

the situation we see with concentrated wastes from animal feed lots, and

therefore the water discharged from aquaponics greenhouses (let's say a 25%

water exchange is occuring) actually represents much less water "used" and

much more stabilized nutrients kept out of the water for a given pound of

animal flesh produced, since much of the nutrients were either translocated

into the plant biomass, or were decomposed into carbon dioxide while trapped

on the gravel (that CO2 then could be partly assimilated by our plants in

the greenhouse), or were incorporated into a very high surface area

bacterial biomass which is the biofilm on the surfaces of the pipes, tanks,

and gravel or perlite in the system.

I think a reasonable "critical control point", (to borrow from my HACCP

training,) for performing an aquaponic water exchange would be a nitrate

level of 100-200 ppm and or a total dissolved solids level of 2000-2500 ppm.

Considering that I have not performed a water exchange in one year (yes,

there were a few spills and a few leaks, but they were minor and haphazard

compared to the total volume of about 25,000 gallons of fish tank culture- I

consider the replacement of the evaporated water with captured rainwater

part of the price of doing business, and so the rainwater replacement should

not be considered a major part of the nutrient and dissolved salts "budget")

I think it is very clear to me that I have proved to myself that I can

produce about 4000 to 5000 lbs of fish with only 25,000 gallons of initial

well water input, and I will only perform a 25 to 50 % water exchange in the

future.  Contrast that with a cattle feed lot, and contrast the total

nutrient export that might take place when I drip irrigate that aquaponic

water onto the outdoor crop in a controlled fashion, when the plants and

soil can absorb it, rather than exposing a compost pile to the rain and

elements for 2 or 3 months.

Consider this.

I would appreciate your thoughts and additions to this perspective.

I think I will have more on this subject at a later date.

Have a great weekend.

Ted

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Subject: Re: live transport

From:    "vpage" 

Date:    Sun, 6 Jun 1999 13:16:26 -0600

I am looking for a  transporter that could move live fish from Minn.  to

Alberta.

Anyone?

Thanks VPage

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| Message 6                                                           |

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Subject: Re: price - swiss chard

From:    STUNTTMAN

Date:    Sun, 6 Jun 1999 16:47:35 EDT

Thanks Stunttman,

  What does that work out to per pound?

Adriana

> I sell green chard for .69$ for a bunch of 6 or 7 large leaves.Red chard for

> .99$ for same amount.

Adriana,

                        I've never bothered to weigh it because my customer 

buys it by the bunch.Next time I harvest i'll wiegh it for you.

                                                                                

                        Charlie

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| Message 7                                                           |

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Subject: Re: Ken's Progress Report + Shiso

From:    "William Brown" 

Date:    Sun, 6 Jun 1999 07:07:08 -1000

We grow the red shiso for personal use.  It is very easy to grow and gets

quite large so ours is in the ground.  We don't use it very often except in

a dried finely chopped condiment form for rice.  It has a strange tangy

almost metallic taste.   I'll check around for other common uses, one is as

flavoring for boiled peanuts.  The green is harder to grow and less common

and I can't tell you too much about it's use.  Around here people usually

sell the plant rather than any parts.  The Asians generally grow their own

if they use it and the rest aren't accustomed to using it so aren't

interested. It does have a nice color and interesting leaf shape/texture.

William Brown mahiwai@cmpmail.com

(aka lettuce@hilo.net)

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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