Aquaponics Digest - Sat 01/08/00


Subject: 
     
Message   1: Archive Subject Policy
             from Bill 

Message   2: H2O Nutrient / Compost
             from Bill 

Message   3: Re: Fw: Greenwater Culture in Israel.
             from "Sam Levy" 

Message   4: Re: ppm for P,K,Ca,Mg in effluent
             from "Sam Levy" 

Message   5: Re: System Thoughts, Bacteria?
             from "Barry Thomas" 

Message   6: Re: H2O Nutrient / Compost
             from "Barry Thomas" 

Message   7: Re: New varieties for Y2K
             from Adriana Gutierrez & Dennis LaGatta 


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| Message 1                                                           |
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Subject: Archive Subject Policy
From:    Bill 
Date:    8 Jan 00 00:02:33 PST

>>*eGroups has a feature allowing editting of archives, even a

>will also have that ability on Jim's site once we're
fully set up.

>  I wonder how many people actually take advantage of that
eGroups feature?
*This is a matter of training the dog.  Not via ignoring the dog, a dog w=
ishes
to please.  A harsh word works ill, but a polite mention does get the
attention, without a beating or unsubbing required, which does nothing go=
od. =

It is as the US Army studies show, a slower improvement in behavior than
Hitler's methods, but with superior side benefits, overall worthwhile.

BTW - you might consider sending separate messages for the many subjects =
to
which you reply.  It will certainly make things easier to thread later.
Paula S&S Aqua Farm

I will surely do as you wish.  I take this in digest form, and have used =
it's
convenience to also reduce my post quanities.  I instruct as to how and w=
hy in
my group, and remind nicely, as you nicely suggested here.

I do believe tho' that whatever 'search' feature you use, multiple words =
in a
'Subject,' will search as well, largely retaining thread integrity, which=

sometimes overlap.  I find searches rare, and the minimal inconvenience o=
f a
side subject tossed in, a minimal hassle for the searcher later, to cull.=


I suggest (to my group) to include the words they would use to search for=
 a
subject.  As I teach, one subject naturally leads/realtes to another, so =
my
posts' Titles, are usually are 3-5 words in descriptive terms.
Respectfully,
Bill




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| Message 2                                                           |
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Subject: H2O Nutrient / Compost
From:    Bill 
Date:    8 Jan 00 00:37:38 PST

>Running the pump continuously poses no threat to the fish
*Tom has eventual issues with low energy also, to address his goal.

The roots must not get just a dribble, unless it covers the
roots, (wets their surface area) almost entirely, for whatever
the time duration is.

With coarse media, (Is it about 1/4" Tom?) a drip may go around
roots, tho' they will try to seek it.  The result would be low
root mass.  That result will be low green mass.  All began with insuffici=
ent
water/nutrient mass when & where (all over) required.

>> How many pounds was the 8" bail you added.
>Suggest that this is evicted.
*I admit the 8" diameter is almost bothersome to me, but it
depends on DO within, and that means, (basically) flow thru'
it (of sufficient amount, with reasonable DO.)  If you can't
tell, open it, smell for hydrogen sulfide amount. (Rotten egg.)
[Note:  This gas deadens the sense of smell, so soon you may say,
"I guess it's not as bad as I thought it was a minute ago.
A few will get a headache from it, but should be safe in this
amount.]  A little smell is Ok, but not excessive!

>> Miracle Grow MAY be sprayed on the tomato / etc leaves.
>I forwarded Adriana's post which was forwarding a post from -
I believe - Joel, because you asked about using it for hydro.

>I recall that I said to use commercial hydroponic nutrient.
Nothing against MG but buying the proper stuff seems best
to start with - one less thing to worry about.

*I want to keep as much on the plants and out of the water as possible
(MG-wise)

*And I must recall differently, but I do recall the earlier suggestion as=
 to
commercially mixed hydro nutrient.  I explaind I cannot use it for sake o=
f
authenticity, in my situation.  For Tom, a leaf only app, and a bit of Ep=
som
(calculate, and proceed gradually - I would not exceed 10% of max calcula=
tion
per week, and would prefer month, until new info is acquired) in the wate=
r, I
feel is OK.  How are Catfish with this folks?  Acid?  Or alkaline?  I've =
seen
their likes in acid river and streams, and dehydrated ponds.

>> MOST fish will adapt to brackish water, slowly.

>*just spraying by hand occasionally?
*As first aid, only, and a one-a-day suppliment, later, if it helps.  Rig=
ht
now, while he accesses his needs, he must try to keep the patient alive, =
upon
which to soon operate.

>> What's your DO? (Well, tell me the water temp, then
>> estimate from the chart, using [for you] sea level.)

>How does this work? DO is surely dependent on more than
temps and pressure?
*Of course.  Other loads reduce it.  But w/o hard gallonage
and fish weight and etc, I must go by feel, and his verbage
SEEMS to indicate a low nutrient level, all around.  Catfish
are somewhat sedentary.  He geats away with little pumping,
so no DO is artificially produced.  It is likely to be
according to temp.  His tank is... somewhat empty.  In fact,
his hay MAY (going out on a limb) be his greatest user of DO.
His algae (mostly gone or trapped) will use some during
specific periods of the diurnal cycle.

But let's not quibble. This is a guessing game without the inputs/invento=
ry. =

Rather like "What's My Line" Show,
done with blindfolds and one question at a time.

>barrythomas@btinternet.com
>PS Yes. I'd like the compost links if you've time.
*Right away my good sir.
(My phone is going up/down on a whim.)
Bill





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| Message 3                                                           |
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Subject: Re: Fw: Greenwater Culture in Israel.
From:    "Sam Levy" 
Date:    Sat, 08 Jan 2000 05:26:30 PST

jim,

sorry for the delay in posting--december was a crazy month.  for a 200 sq m 
concrete floor i would guess that 8 inches would be thick enough--although 
you might be able to getaway with 6 inches.  i would consult w/a 
construction engineer over depth and correct diameter reinforcements as i 
believe that some of this will depend on the type of soil & location.  
besides a thickened area under the walls, you might need extra support 
around the draining basin.  it is important that the concrete have a good 
finish ("helicopter") as i believe this helps keep the water away from the 
steel reinforcing bars.  although you may need it slightly "roughed" after 
finishing--so that the pond can be worked in without slipping when full.

as for the 45 degree drainage basin, you might see if you can use a pre-cast 
unit of plastic or concrete like the kind used drainage lines.  i operated 
plastic lined earthen ponds which used a concrete drain basin that was 
circular, 1 meter in diameter, about 6 inches deep at the edge and bout 10 
inches deep in the center w/an 8 inch drain pipe & it seemed to work 
reasonably well (if i were to do it over, i'd probably opt for a 10 inch or 
12 inch drain pipe).

i recently spoke with a friend who built a series of 6 ponds using 
cinderblock lined with elvaloi (a pvc polymer with an additive that is 
designed to maintain the flexibility of the plastic over long periods of 
time).  he told me that when he expands, he'd consider corrugated metal 
sides w/plastic liner in order to save on construction costs.  i mention 
this knowing full well that the budgeting considerations facing you may be 
quite different than my friend.

i am a big fan of polyethylene as it is strong, longlasting, deters 
attachment of filamentatious algae, seems to deter chewing creatures, and is 
less pricey than other polymer materials.

it does have a few drawbacks:

it does not lie flat on the pond bottom--with juveniles or thinly populated 
ponds this can create "settlement areas" that do not drain with normal 
flushing procedures (we would periodcally use brooms while draining the pond 
to move out this material).  once the fish are larger, and the pond is 
stocked to around 8 kg/cu m, the movement of the fish should keep this stuff 
suspended until it settles in the middle.  by the way, double check how much 
spare metrage you need to lay to compensate for winter contraction of the 
plastic--the more extra you add the more the lining may look like "elephant 
skin"--however, if there's not enough, you'll quickly have problems 
w/tearing that may not be covered by the warranty.

it requires specialised equipment to repair.  although we were able to make 
small temporary patches using hot-air welds, we needed to bring down a 
technician w/special equipment to make "permanent" repairs.  holes were 
typically the result of a stone trapped under the plastic the gradually 
worked its way through.  tears were generally the result of improper 
equipment handling (esp aspirators).  neither holes nor tears were major 
problems & i only mention them so that you have the information.

it is very slippery--we installed a "walkway" of roughened material in each 
pond from edge to center.  (we also created a "work area" with an additional 
layer of this material for weighing , feeding, replacing aerators &c.

as for systems out of use, i don't really have any statistics at the moment 
however, after many years of growth i believe that the isreali market for 
fresh fish has "matured" resulting in lowered prices for 
producers--especially for tilapia.

sam



>From: "James Rakocy" 
>Subject: Re: Fw: Greenwater Culture in Israel.

>
>Sam, We are working on greenwater technology here in the Virgin Islands.  
>We
>plan to build two circular greenwater tanks early next year.  They will be
>200 m2.  In our experiments so far we have been able to produce 17 kg/m3
>using Nile tilapia.  Our water exchange rate is much lower, less than 1%.
>We only remove water containing sludge, which is a nice dark green color,
>indicating the removal of dead algal cells.  I would be interested to learn
>about construction techniques.  We plan to build one tank with a standard
>block wall and the tank will be lined with 30 mil high density 
>polyethylene.
>We will slope the bottom to a center drain by 1 to 2% and insert a 1 m3 
>cone
>(45 degree slope made of thicker lining material) in the center of the 
>tank.
>The other method will use a speed block wall and a concrete bottom.  I
>understand that speed blocks involves a combination of poured concrete core
>and a block outer wall, almost like a permanent form.  I want to compare 
>the
>cost, ease of construction and durability of these methods.  I'm not too
>familiar with concrete work.  I would like to know the best way to pour a
>200 m2 concrete floor.  How thick should it be?  What type of reinforcing 
>is
>best?  There will be a 18 inch wide by 1 foot deep footing around the
>perimeter.  How does one assure a good seal between the wall and the 
>footing
>and the floor and the footing?  Also, how does one make a 45 degree cone 
>out
>of concrete?  Does it require a form or can you use a drier mix and shape 
>it
>without a form.  I understand that many Israeli greenwater systems are out
>of use?  Is this true and why?  Anyone good with concrete? Jim R.
>





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| Message 4                                                           |
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Subject: Re: ppm for P,K,Ca,Mg in effluent
From:    "Sam Levy" 
Date:    Sat, 08 Jan 2000 05:47:01 PST

kevin,

although there is some literature on this subject, i believe you might do 
better to actually monitor in order to learn your system and its limits.  
fish will excrete somewhere between 75 - 85% of their nitrogen intake (from 
protein) as ammonia (nh3 - nh4+)(most) or in solids.  nitrates may be from 
the water source or from the oxidation of ammonia by bacteria (first to 
nitrite then to nitrate). the toxicity of ammonia (although you didn't ask 
this) is dependent on pH--which also mediates the availability of the other 
nutrients you mentioned to the plants. (since we touched the subject, the 
toxicity of nitrite is mediated by the chloride concentration of the culture 
water.) the P content of the effluent is definately related to the feed 
used.

you might want to compare the prices of chemical test kits for these 
nutrients and the cost of having them performed periodically by a lab and 
decide what's most suited for you.

sam


>From: "KevinLReed" 
>Subject: ppm for P,K,Ca,Mg in effluent
>Date: Thu, 6 Jan 2000 17:59:35 +0200
>
>Aloha,
>I wonder if anyone has a breakdown on the fish effluent. Is the water 
>mostly nitrate now or is there any significant level of phosphorous, 
>potassium, calcium or magnesium.  Is there any way to adjust these by what 
>I feed the fish? I am having a " soil test" done on the local coral to see 
>how much  Ca it will provide per/ pound. I am trying to make a 
>determination on effluent replacement of fertilizers and soil amendments in 
>a pounds per acre format to show the local farmers.
>Any thoughts?
>
>Aloha Nui Loa,
>Kevin





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| Message 5                                                           |
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Subject: Re: System Thoughts, Bacteria?
From:    "Barry Thomas" 
Date:    Sat, 8 Jan 2000 16:58:08 -0000

Tom,

> This list has the nicest people I have encountered
> anywhere, and I'm on a lot of lists. Thanks for your
> wise comments. Alotta good info.

Oh... you know... shoulders of giants etc.   ;)

Seriously, what I suggested was basically just generalised across from
hydro and should be treated with appropriate caution.

> You are suggesting that I don't do the interval
> thing, but just let the pump keep pumping and keep
> the roots wet/immersed? It seems like too much,

Yes. Not a total solution on it's own but seems a necessary part.
Hopefully,  suggestions from others with more direct aqua experience
will help with the fishier side of things.

Barry
barrythomas@btinternet.com





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| Message 6                                                           |
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Subject: Re: H2O Nutrient / Compost
From:    "Barry Thomas" 
Date:    Sat, 8 Jan 2000 17:09:02 -0000

----- Original Message ----- 
From: Bill 
To: 
Sent: Saturday, January 08, 2000 8:37 AM
Subject: H2O Nutrient / Compost


> >Running the pump continuously poses no threat to the fish
> *Tom has eventual issues with low energy also, to address his goal.
> 
> The roots must not get just a dribble, unless it covers the
> roots, (wets their surface area) almost entirely, for whatever
> the time duration is.

*Replied off-list*

Barry
barrythomas@btinternet.com




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| Message 7                                                           |
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Subject: Re: New varieties for Y2K
From:    Adriana Gutierrez & Dennis LaGatta 
Date:    Sat, 08 Jan 2000 19:25:11 -0500

Thanks William for your comprehensive response.  I tried Mascara and it
is very similar to Cerize but doesn't grow as well or as colorful.  I
wouldn't waste my money on it.

Adriana

William Brown wrote:
> 
> Green Ice from Burpee is still my main crop for green lettuce.  Handles the
> sub-tropical heat well, can get up to a pound in weight, great color, flavor
> and smell.







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