Aquaponics Digest - Mon 03/19/01




Message   1: pH, DO, etc...
             from "Devon Williams" 

Message   2: Re: pH, DO, etc...
             from "KenHale" 

Message   3: Re: pH, DO, etc...
             from "Devon Williams" 

Message   4: Re: pH, DO, etc...
             from "Devon Williams" 

Message   5: Re: pH, DO, etc...
             from "KenHale" 

Message   6: Re: Aquaponics Short Course at UVI "STEVE SPRING"
             from "STEVE SPRING" 

Message   7: Re: Where is every one?
             from "STEVE SPRING" 

Message   8: Re: pH, DO, etc...
             from S & S Aqua Farm 

Message   9: Re: pH, DO, etc...
             from "Devon Williams" 

Message  10: Re: pH, DO, etc...
             from "Devon Williams" 

Message  11: Re: pH, DO, etc...
             from "STEVE SPRING" 

Message  12: Re: pH, DO, etc...
             from "Devon Williams" 

Message  13: Re: "fertilizing" tanks
             from "Devon Williams" 

Message  14: Red Tilapia Hybrids Available
             from "Charlie Shultz" 

Message  15: Re: "fertilizing" tanks
             from "TGTX" 

Message  16: Re: Where is every one?
             from marc 'at' aculink.net

Message  17: Re: "fertilizing" tanks
             from "Devon Williams" 

Message  18: Herbicide
             from marc 'at' aculink.net



| Message 1  

Subject: pH, DO, etc...
From:    "Devon Williams" 
Date:    Mon, 19 Mar 2001 10:11:59 -0500

Hi everyone.  Now that I am pretty close to ready with my system, I have 
been testing the water, and came across a few questions...

At what pH level do you keep you water?  I am getting conflicting ideas on 
this...some say below 7.6 is best, while others say 8.2 is best.

What DO level is appropriate?

Do you all measure hardness (carbonate and general), and if so what is an 
appropriate level for this?

At what level do you try to keep ammonia?  I don't have an ammonia reading 
yet since I have no living creatures adding it to the system, but thought 
I'd ask anyway.

Any other tips on appropriate safe readings would be appreciated!

Thanks!



Devon Williams
Beer Belly Brothers Brewing
Watkinsville, GA

  ooooo
  |..oo=|
  |...o |
  |...| |
  |...|=|
  |___|

_________________________________________________________________





| Message 2  

Subject: Re: pH, DO, etc...
From:    "KenHale" 
Date:    Mon, 19 Mar 2001 09:22:58 -0600

6.8 -- the lower you maintain" ph" the less toxic your waste is to your
fish. -----On oxygen- 6-8 ppm is the goal -----Ken Hale/Boatcycle Fish Farm
Supply
----- Original Message -----
From: "Devon Williams" 
To: 
Sent: Monday, March 19, 2001 9:11 AM
Subject: pH, DO, etc...


_________________________________________________________________
> 
>
>




| Message 3  

Subject: Re: pH, DO, etc...
From:    "Devon Williams" 
Date:    Mon, 19 Mar 2001 10:49:34 -0500

Thanks Ken.  My pH is at 7.6 right now...how would you suggest lowering that 
level without causing problems with the fish?

Devon


>From: "KenHale" 
>Reply-To: aquaponics 'at' townsqr.com
>To: 
>Subject: Re: pH, DO, etc...
>Date: Mon, 19 Mar 2001 09:22:58 -0600
>
>6.8 -- the lower you maintain" ph" the less toxic your waste is to your
>fish. -----On oxygen- 6-8 ppm is the goal -----Ken Hale/Boatcycle Fish Farm
>Supply
>----- Original Message -----
>From: "Devon Williams" 
>To: 
>Sent: Monday, March 19, 2001 9:11 AM
>Subject: pH, DO, etc...
>
>
>_________________________________________________________________
> > 
> >
> >
>

_________________________________________________________________





| Message 4  

Subject: Re: pH, DO, etc...
From:    "Devon Williams" 
Date:    Mon, 19 Mar 2001 10:52:00 -0500

Obviously since I don't have fish yet, there aren't any fish to kill, but 
for future reference...


>From: "Devon Williams" 
>Reply-To: aquaponics 'at' townsqr.com
>To: aquaponics 'at' townsqr.com
>Subject: Re: pH, DO, etc...
>Date: Mon, 19 Mar 2001 10:49:34 -0500
>
>Thanks Ken.  My pH is at 7.6 right now...how would you suggest lowering 
>that
>level without causing problems with the fish?
>
>Devon
>
>
>>From: "KenHale" 
>>Reply-To: aquaponics 'at' townsqr.com
>>To: 
>>Subject: Re: pH, DO, etc...
>>Date: Mon, 19 Mar 2001 09:22:58 -0600
>>
>>6.8 -- the lower you maintain" ph" the less toxic your waste is to your
>>fish. -----On oxygen- 6-8 ppm is the goal -----Ken Hale/Boatcycle Fish 
>>Farm
>>Supply
>>----- Original Message -----
>>From: "Devon Williams" 
>>To: 
>>Sent: Monday, March 19, 2001 9:11 AM
>>Subject: pH, DO, etc...
>>
>>
>>_________________________________________________________________
>> > 
>> >
>> >
>>
>
>_________________________________________________________________
>
>

_________________________________________________________________





| Message 5  

Subject: Re: pH, DO, etc...
From:    "KenHale" 
Date:    Mon, 19 Mar 2001 10:21:37 -0600

If you are very,VERY careful sulfuric acid in small amounts (1 ounce to 50
gal of water to treat 1000 gal) and then retest-or-alum. sulfate  'at'  5 lbs at
a time and retest. Ken
----- Original Message -----
From: "Devon Williams" 
To: 
Sent: Monday, March 19, 2001 9:52 AM
Subject: Re: pH, DO, etc...


> Obviously since I don't have fish yet, there aren't any fish to kill, but
> for future reference...
>
>
> >From: "Devon Williams" 
> >Reply-To: aquaponics 'at' townsqr.com
> >To: aquaponics 'at' townsqr.com
> >Subject: Re: pH, DO, etc...
> >Date: Mon, 19 Mar 2001 10:49:34 -0500
> >
> >Thanks Ken.  My pH is at 7.6 right now...how would you suggest lowering
> >that
> >level without causing problems with the fish?
> >
> >Devon
> >
> >
> >>From: "KenHale" 
> >>Reply-To: aquaponics 'at' townsqr.com
> >>To: 
> >>Subject: Re: pH, DO, etc...
> >>Date: Mon, 19 Mar 2001 09:22:58 -0600
> >>
> >>6.8 -- the lower you maintain" ph" the less toxic your waste is to your
> >>fish. -----On oxygen- 6-8 ppm is the goal -----Ken Hale/Boatcycle Fish
> >>Farm
> >>Supply
> >>----- Original Message -----
> >>From: "Devon Williams" 
> >>To: 
> >>Sent: Monday, March 19, 2001 9:11 AM
> >>Subject: pH, DO, etc...
> >>
> >>
> >>_________________________________________________________________
> >> > 
> >> >
> >> >
> >>
> >
> >_________________________________________________________________
> >
> >
>
> _________________________________________________________________
> 
>
>




| Message 6  

Subject: Re: Aquaponics Short Course at UVI "STEVE SPRING"
From:    "STEVE SPRING" 
Date:    Mon, 19 Mar 2001 10:20:23 -0600

Hi Jay and thanks,

I just feel like I was starting to stick my nose where it didn't belong & it
is ultimately, of course, up to Dr. J.  There are several of us who are very
interested. Would be nice if we could get Dr. J. and the UVI staff
interested too. "Hey, I could go for snorkeling and BBQ in February!!" It is
around February that my "cabin fever" becomes almost terminal.

And, Hey, I just found that a fellow list subscriber, Bruce Schreiber
(dog-gone it, I'm going to misspell his last name.) lives only about 30
miles from me. We are going to get together and check out the Tropical fish
and the "earthbox"..As I say, "LOVE THIS LIST!!" (Maybe he wants to go to
the UVI in February.) (See, I said I wasn't going to get involved with this
again and I'm not....I'm not.....I'm not!!!)

Take care.....we'll see.....thanks agan.......Steve   :)


----- Original Message -----
From: "JAlan Aufderheide" 
To: 
Sent: Saturday, March 17, 2001 4:24 AM
Subject: Re: Aquaponics Short Course at UVI "STEVE SPRING"


Steve -  For what's it's worth I agree with you completely.

I too would LOVE to do that UVI course . . .

I too have other priorities in the summer.

Yes UVI would be a fabulous place to go . . . in the winter . . .

pero, lo siento mucho . . .

Donald just doesn't get it.

Jay

----- Original Message -----
From: STEVE SPRING 
To: 
Sent: Saturday, March 17, 2001 4:34 PM
Subject: Re: Aquaponics Short Course at UVI "STEVE SPRING"


> Hi Donald,
>
> Thank you very much for responding.
>
> I am 100% certain that your intern is working, sweating and learning a
> lot...a tremendous amount of information and experience is available from
> you guys.
>
> But, I'm talking about those of us who would love to visit your facility
and
> learn also. But......we aren't available in the summertime.
>
> I, ABSOLUTELY, will not pursue this anymore. I feel as if I am starting to
> "step on toes" & I don't want to do this. I thought it would be a
"win-win"
> situation.
>
> Paula told me that she didn't think that Dr. J.had  time for a winter
course
> and even if he had, maybe it would be better if he presented it himself.
> (Not some dumbo like me....my words....not hers.)
>
> I was just trying to present something that might work.
>
> Later.....and thanks again for responding.........Steve
>
> ----- Original Message -----
> From: "Donald Bailey" 
> To: 
> Sent: Friday, March 16, 2001 9:33 AM
> Subject: Re: Aquaponics Short Course at UVI "STEVE SPRING"
>
>
> Dear Steve:
> Our summertime short course includes a half day (morning) in a classroom
> and a half day (afternoon) in the field.  If you got on a plane down
> here next week you could be an intern for as long as you like.  There
> would be no formal classroom time and you would sweat a little more but
> you would be harvesting fish and vegetables, feeding 3x a day, grading
> and sorting the juveniles, installing liners in our new hydroponic
> tanks, laying blocks for our new 55,000 gallon greenwater tank AND you
> would have a 5:1 teacher/student ratio to tell you all the details, good
> and bad, of our systems.
>
> I have one intern here right now who is, today, sorting red tilapia
> brood fish and collecting eggs and fry.  She is soaking wet.  She will
> sort the males from females and haul them back to their separate tanks.
> She will enumerate the fry.  She will clean the eggs and get a hatching
> jar running.  And that is just her morning work.  In the afternoon she
> is transplanting cucumber, pak choi, collards and basil.
>
> There is plenty to do so come on down.
>
> > Message   3: Re: Aquaponics Short Course at UVI
> >              from "STEVE SPRING" 
>
> > 
> > | Message 3  
> > 
> > Subject: Re: Aquaponics Short Course at UVI
> > From:    "STEVE SPRING" 
> > Date:    Thu, 15 Mar 2001 11:47:28 -0600
> >
> > Hi Donald,
> >
> > There are still several people who would be interested in a winter
course.
> I
> > am still in the background as requested. I believe that there is a
market
> > for a winter course at UVI . Hey, don't you people still snorkel in
> > February?
> >
> > I'm sure Dr. J. remembers how bad we want to get out in Feb., Mar., ??
Dr.
> > J. said that he didn't think that I could get 5 people. Trust me. I have
> had
> > much more than that contact me.
> >
> > Just something to think about.
> >
> > I would love to attend the course, but I just can't in the summertime.
> >
> > Sorry if I am a P.I.A. I just am.
> >
> > Take care......Steve
>
>





| Message 7  

Subject: Re: Where is every one?
From:    "STEVE SPRING" 
Date:    Mon, 19 Mar 2001 10:29:35 -0600

5 X 5 Bruce, Loud & clear. No problems.

Steve
 

----- Original Message ----- 
From: "Bruce Schreiber" 
To: 
Sent: Sunday, March 18, 2001 3:43 PM
Subject: Re: Where is every one?


Marc      No you got me wrong I didn't think that I was kicked off of
the list .Only that yahoo wasn't abel to deliver emails to me for some
reason and I got worried because I had received (0)emails from our
Aquaponic list over night and into the morning I usually get 20 or more
on average total from all sources so I thought my server was on the
blink and was trying to find out.I could care less about the other lists
this one is the good one
                             Bruce





| Message 8  

Subject: Re: pH, DO, etc...
From:    S & S Aqua Farm 
Date:    Mon, 19 Mar 2001 10:24:30 -0600

At 10:11 AM 03/19/2001 -0500, you wrote:
>Hi everyone.  Now that I am pretty close to ready with my system, I have 
>been testing the water, and came across a few questions...
>
>At what pH level do you keep you water?  I am getting conflicting ideas on 
>this...some say below 7.6 is best, while others say 8.2 is best.

Devon - our well water measures 7.3, and we were told plants need pH in the
6.X range for best growth.  While we were looking for safe ways to adjust
the pH, it seems that the gravel in the beds acted as a buffering "agent" so
that it became unnecssary.

What level is your incoming water?

Paula

PS:  Love this sig line!


>Devon Williams
>Beer Belly Brothers Brewing
>Watkinsville, GA
>
>  ooooo
>  |..oo=|
>  |...o |
>  |...| |
>  |...|=|
>  |___|
>
>_________________________________________________________________
>
>
>




| Message 9  

Subject: Re: pH, DO, etc...
From:    "Devon Williams" 
Date:    Mon, 19 Mar 2001 11:55:57 -0500

My incoming water is at about 7.2.

As far as the signature goes, that is my "other" love.  My brother and I 
have been brewing beer (and award winning beers at that) for the past ~4 
years...  The name fits us pretty well!!!  :-)

Devon

>From: S & S Aqua Farm 
>Reply-To: aquaponics 'at' townsqr.com
>To: aquaponics 'at' townsqr.com
>Subject: Re: pH, DO, etc...
>Date: Mon, 19 Mar 2001 10:24:30 -0600
>
>At 10:11 AM 03/19/2001 -0500, you wrote:
> >Hi everyone.  Now that I am pretty close to ready with my system, I have
> >been testing the water, and came across a few questions...
> >
> >At what pH level do you keep you water?  I am getting conflicting ideas 
>on
> >this...some say below 7.6 is best, while others say 8.2 is best.
>
>Devon - our well water measures 7.3, and we were told plants need pH in the
>6.X range for best growth.  While we were looking for safe ways to adjust
>the pH, it seems that the gravel in the beds acted as a buffering "agent" 
>so
>that it became unnecssary.
>
>What level is your incoming water?
>
>Paula
>
>PS:  Love this sig line!
>
>
> >Devon Williams
> >Beer Belly Brothers Brewing
> >Watkinsville, GA
> >
> >  ooooo
> >  |..oo=|
> >  |...o |
> >  |...| |
> >  |...|=|
> >  |___|
> >
> >_________________________________________________________________
> >
> >
> >
>

_________________________________________________________________





| Message 10 

Subject: Re: pH, DO, etc...
From:    "Devon Williams" 
Date:    Mon, 19 Mar 2001 11:58:21 -0500

Paula,

The gravel in my bed is granite.  any clue if that might react the same way 
as your "pea" gravel?


>From: S & S Aqua Farm 
>Reply-To: aquaponics 'at' townsqr.com
>To: aquaponics 'at' townsqr.com
>Subject: Re: pH, DO, etc...
>Date: Mon, 19 Mar 2001 10:24:30 -0600
>
>At 10:11 AM 03/19/2001 -0500, you wrote:
> >Hi everyone.  Now that I am pretty close to ready with my system, I have
> >been testing the water, and came across a few questions...
> >
> >At what pH level do you keep you water?  I am getting conflicting ideas 
>on
> >this...some say below 7.6 is best, while others say 8.2 is best.
>
>Devon - our well water measures 7.3, and we were told plants need pH in the
>6.X range for best growth.  While we were looking for safe ways to adjust
>the pH, it seems that the gravel in the beds acted as a buffering "agent" 
>so
>that it became unnecssary.
>
>What level is your incoming water?
>
>Paula
>
>PS:  Love this sig line!
>
>
> >Devon Williams
> >Beer Belly Brothers Brewing
> >Watkinsville, GA
> >
> >  ooooo
> >  |..oo=|
> >  |...o |
> >  |...| |
> >  |...|=|
> >  |___|
> >
> >_________________________________________________________________
> >
> >
> >
>

_________________________________________________________________





| Message 11 

Subject: Re: pH, DO, etc...
From:    "STEVE SPRING" 
Date:    Mon, 19 Mar 2001 11:05:46 -0600

Hi Devon,

I'm going to jump in here just a minute. Only because I didn't see a
response to your question. 7.6 pH is o.k. Don't mess with it. You are still
"basically" in the neutral range. You are slightly in the alkalotic range of
pH, but only slightly. Remember, 7.0 is neutral. Don't sweat it, and DON'T
MESS WITH IT. Don't try to get too finite, you will go crazy.

Steve

----- Original Message -----
From: "Devon Williams" 
To: 
Sent: Monday, March 19, 2001 9:52 AM
Subject: Re: pH, DO, etc...


Obviously since I don't have fish yet, there aren't any fish to kill, but
for future reference...


>From: "Devon Williams" 
>Reply-To: aquaponics 'at' townsqr.com
>To: aquaponics 'at' townsqr.com
>Subject: Re: pH, DO, etc...
>Date: Mon, 19 Mar 2001 10:49:34 -0500
>
>Thanks Ken.  My pH is at 7.6 right now...how would you suggest lowering
>that
>level without causing problems with the fish?
>
>Devon
>
>
>>From: "KenHale" 
>>Reply-To: aquaponics 'at' townsqr.com
>>To: 
>>Subject: Re: pH, DO, etc...
>>Date: Mon, 19 Mar 2001 09:22:58 -0600
>>
>>6.8 -- the lower you maintain" ph" the less toxic your waste is to your
>>fish. -----On oxygen- 6-8 ppm is the goal -----Ken Hale/Boatcycle Fish
>>Farm
>>Supply
>>----- Original Message -----
>>From: "Devon Williams" 
>>To: 
>>Sent: Monday, March 19, 2001 9:11 AM
>>Subject: pH, DO, etc...
>>
>>
>>_________________________________________________________________
>> > 
>> >
>> >
>>
>
>_________________________________________________________________
>
>

_________________________________________________________________






| Message 12 

Subject: Re: pH, DO, etc...
From:    "Devon Williams" 
Date:    Mon, 19 Mar 2001 12:11:57 -0500

Thanks Steve.  That is generally my approach to most anything, but it 
doesn't hurt to at least know what the "perfect world" target would be.  I 
appreciate your input!

Devon


>From: "STEVE SPRING" 
>Reply-To: aquaponics 'at' townsqr.com
>To: 
>Subject: Re: pH, DO, etc...
>Date: Mon, 19 Mar 2001 11:05:46 -0600
>
>Hi Devon,
>
>I'm going to jump in here just a minute. Only because I didn't see a
>response to your question. 7.6 pH is o.k. Don't mess with it. You are still
>"basically" in the neutral range. You are slightly in the alkalotic range 
>of
>pH, but only slightly. Remember, 7.0 is neutral. Don't sweat it, and DON'T
>MESS WITH IT. Don't try to get too finite, you will go crazy.
>
>Steve
>
>----- Original Message -----
>From: "Devon Williams" 
>To: 
>Sent: Monday, March 19, 2001 9:52 AM
>Subject: Re: pH, DO, etc...
>
>
>Obviously since I don't have fish yet, there aren't any fish to kill, but
>for future reference...
>
>
> >From: "Devon Williams" 
> >Reply-To: aquaponics 'at' townsqr.com
> >To: aquaponics 'at' townsqr.com
> >Subject: Re: pH, DO, etc...
> >Date: Mon, 19 Mar 2001 10:49:34 -0500
> >
> >Thanks Ken.  My pH is at 7.6 right now...how would you suggest lowering
> >that
> >level without causing problems with the fish?
> >
> >Devon
> >
> >
> >>From: "KenHale" 
> >>Reply-To: aquaponics 'at' townsqr.com
> >>To: 
> >>Subject: Re: pH, DO, etc...
> >>Date: Mon, 19 Mar 2001 09:22:58 -0600
> >>
> >>6.8 -- the lower you maintain" ph" the less toxic your waste is to your
> >>fish. -----On oxygen- 6-8 ppm is the goal -----Ken Hale/Boatcycle Fish
> >>Farm
> >>Supply
> >>----- Original Message -----
> >>From: "Devon Williams" 
> >>To: 
> >>Sent: Monday, March 19, 2001 9:11 AM
> >>Subject: pH, DO, etc...
> >>
> >>
> >>_________________________________________________________________
> >> > 
> >> >
> >> >
> >>
> >
> >_________________________________________________________________
> >
> >
>
>_________________________________________________________________
>
>
>

_________________________________________________________________





| Message 13 

Subject: Re: "fertilizing" tanks
From:    "Devon Williams" 
Date:    Mon, 19 Mar 2001 13:23:01 -0500

O.k., so I assume since I got ZERO responses to my original post on this 
subject (see below) that no one on this list does this... OR, was everyone 
just busy that day?...;-)

Devon


>From: "Devon Williams" 
>Reply-To: aquaponics 'at' townsqr.com
>To: aquaponics 'at' townsqr.com
>Subject: "fertilizing" tanks
>Date: Thu, 08 Mar 2001 08:42:59 -0500
>
>Hi everyone.
>
>In the reading that I've done dealing with Aquaculture, I've noticed that
>fertilizing the pond is good practice in order to raise the amount of
>phytoplankton and zooplankton in the water.  Is this practice also used in
>Aquaponics?  My gut says, "no", but I'm not sure about it.
>
>If you don't fertilize, then what suggestions do any of you have for 
>bumping
>up those little critters? Or is it just not necessary?
>
>Thanks!
>
>Devon Williams
>
>OH, BTW I have updated my website's movie page if anyone is 
>interested...you
>can find it at
>http://www.mindspring.com/~mcconnellms/staff/dwilliams/projects.htm
>
>
>_________________________________________________________________
>
>

_________________________________________________________________





| Message 14 

Subject: Red Tilapia Hybrids Available
From:    "Charlie Shultz" 
Date:    Mon, 19 Mar 2001 18:32:49

Please note the email addresses below for Don or John if you are interested 
in obtaining any of these fish.  Please do not respond personally to me or 
to this list.

Thanks,
Charlie



Hello List Members:

We at the University of the Virgin Islands are often asked to provide
broodfish.  Normally we have none available for sale, as we are not in
the broodfish market.  However, we are currently undergoing massive
breeding of our hybrid red tilapia to establish a new year-class.  These
fish were originally hybridized in Florida and made their way to us via
Jamaica about 15 years ago.

Past results indicate that the offspring of this breeding will give us:
        Approximately 50% male, 50% female
        47% of the fish will be perfectly colored (pinkish red)
        28% of the fish will have 1-5 small spots
        15% of the fish will be mottled
        10% of the fish will be discarded as runts or deformed

Typical production results are as follows:
(sex-reversed male population cultured from 50g to 500g  'at'  28°C)
Growth rate:    >3.0 g/day
FCR:            ˜ 1.6
Survival:       95+%

These fish can be acclimated to full-strength seawater (36 ppt) and grow
at comparable rates.

Fecundity of these fish varies according to management (seasonal vs.
year-around spawning), but is typically 200 fry/lb. of female for each
spawning event.

Being an isolated population for 15 years, our fish have no track record
of viral, parasitic, or bacterial diseases.

Dress-out characteristics:
        85% head-on, gutted and scaled
        34% skinless fillet, pin-bones removed

We recommend buying at least 400 fish.  After they reach 50g, the best
fish can be hand-sexed and selected for breeding.

We will ship up to 1,000 fish per box (˜ 1 g fish).

Cost is $1 per fish + $90 shipping and handling per box.

Fish will be shipped within 24 hours via express delivery.

Note: In accordance with the Lacey Act, fish cannot be delivered to all
locations.  We will determine legality for your area with local
authorities before shipment.

For further information or to place an order, please contact John Martin
(jmartin 'at' webmail.uvi.edu) or Don Bailey (dbailey 'at' webmail.uvi.edu),
or call (340) 692-4020.

--
John M. Martin
Research Specialist II, Aquaculture
University of the Virgin Islands, AES
RR 2, Box 10,000 Kingshill
St. Croix, USVI  00850
ph.#  (340) 692-4037
fax.# (340) 692-4035

_________________________________________________________________________





| Message 15 

Subject: Re: "fertilizing" tanks
From:    "TGTX" 
Date:    Mon, 19 Mar 2001 13:05:03 -0600

Devon,

Generally, the nutrient input to the system comes from the fish feed, which
is processed by the bacteria in the water column and on the surface of the
growing media which in turn provides nutrients to the plants.

I have, as has Tom and Paula, and a number of others on this list no doubt,
used fish emulsion, seaweed extract, etc., added directly  to the water at
certain points.  I even added alfalfa powder and I believe the Tilapia
eventually consumed that in their forage efforts at the bottom of the tank
and in suspension.  I would like to explore the use of alfalfa powder as a
fertilizer supplement in aquaponic systems more thoroughly and
experimentally when next I have the chance.  I believe it is O.K. to do this
kind of supplemental fertilization periodically, or you could even run the
system without fish and use various combinations of "organic" supplements
and I'll betcha you could do pretty well with the plant end of things.  In
my system, before I put up the shade cloth, I would get a pretty healthy
algae bloom in my tanks subsequent to fertilization with fish emulsion and
seaweed extract.  I had 6 tanks buried in the ground inside the greenhouse,
each of which held about 4000 to 4500 gallons or so normal operating volume.
I scoped out the green blooms back at my alma mater (local university), but
the specie's name escapes me now.  It was a unicellular flagellated green
alga, which I suspect the fingerlings carried on them or in them when I
stocked the tanks with my Tilapia from Florida.

It was an excellent food base for the little guys and I believe the biomass
of the algae was caught on the pea gravel and provided a long term "time
release" plant fertlizer as they died and the algal biomass decomposed on
the surface of the gravel.  Problems that can arise with constant greenwater
culture are associated with exponential growth of the microalgae and
detritus based heterotrophic bacterial populations ....a kind of boom and
bust cycle...and of course there is always the added oxygen demand from that
much respiring biomass at night, which means lots of oxygen must be
introduced into the system at all times.  Dr. Jim Rackocy and crew can speak
to this greenwater topic eloquently, I am sure, especially with respect to
expected boom and bust phases, expected flush and refill maintance times or
schedules, etc..

The greenwater culture system is both algal and heterotrophic bacteria based
(within the water column).  I was not a deliberate practitioner of
greenwater culture, but it developed for a period of oh, I guess a month or
so within my system, and I was pleased to see it as long as the DO2 was
always O.K., which can be a challenge sometimes.

Bottom line is I would wager that most aquaponics practioners on this list
have mostly "clear water" systems, if that is a loose enough but appropriate
term....perhaps stained a bit with tannic acids, other Dissolved Organic
Carbon species present from feeds and other inputs over time, and a bit of
turbidity, but not much.

Hope that helps.

Tedzo.

> O.k., so I assume since I got ZERO responses to my original post on this
> subject (see below) that no one on this list does this... OR, was everyone
> just busy that day?...;-)
>
> Devon





| Message 16 

Subject: Re: Where is every one?
From:    marc 'at' aculink.net
Date:    Mon, 19 Mar 2001 12:16:55 -0700


dITTO'S,
mARC

> ----- Original Message -----
> From: "Bruce Schreiber" 
..SNIP..

I could care less about the other lists
> this one is the good one
>                              Bruce



| Message 17 

Subject: Re: "fertilizing" tanks
From:    "Devon Williams" 
Date:    Mon, 19 Mar 2001 14:15:24 -0500

Thanks Ted.  That does help.  Thanks for the time you put into your answer.  
I will be holding onto this post for later "digestion" (no pun).

Devon


>From: "TGTX" 
>Reply-To: aquaponics 'at' townsqr.com
>To: 
>Subject: Re: "fertilizing" tanks
>Date: Mon, 19 Mar 2001 13:05:03 -0600
>
>Devon,
>
>Generally, the nutrient input to the system comes from the fish feed, which
>is processed by the bacteria in the water column and on the surface of the
>growing media which in turn provides nutrients to the plants.
>
>I have, as has Tom and Paula, and a number of others on this list no doubt,
>used fish emulsion, seaweed extract, etc., added directly  to the water at
>certain points.  I even added alfalfa powder and I believe the Tilapia
>eventually consumed that in their forage efforts at the bottom of the tank
>and in suspension.  I would like to explore the use of alfalfa powder as a
>fertilizer supplement in aquaponic systems more thoroughly and
>experimentally when next I have the chance.  I believe it is O.K. to do 
>this
>kind of supplemental fertilization periodically, or you could even run the
>system without fish and use various combinations of "organic" supplements
>and I'll betcha you could do pretty well with the plant end of things.  In
>my system, before I put up the shade cloth, I would get a pretty healthy
>algae bloom in my tanks subsequent to fertilization with fish emulsion and
>seaweed extract.  I had 6 tanks buried in the ground inside the greenhouse,
>each of which held about 4000 to 4500 gallons or so normal operating 
>volume.
>I scoped out the green blooms back at my alma mater (local university), but
>the specie's name escapes me now.  It was a unicellular flagellated green
>alga, which I suspect the fingerlings carried on them or in them when I
>stocked the tanks with my Tilapia from Florida.
>
>It was an excellent food base for the little guys and I believe the biomass
>of the algae was caught on the pea gravel and provided a long term "time
>release" plant fertlizer as they died and the algal biomass decomposed on
>the surface of the gravel.  Problems that can arise with constant 
>greenwater
>culture are associated with exponential growth of the microalgae and
>detritus based heterotrophic bacterial populations ....a kind of boom and
>bust cycle...and of course there is always the added oxygen demand from 
>that
>much respiring biomass at night, which means lots of oxygen must be
>introduced into the system at all times.  Dr. Jim Rackocy and crew can 
>speak
>to this greenwater topic eloquently, I am sure, especially with respect to
>expected boom and bust phases, expected flush and refill maintance times or
>schedules, etc..
>
>The greenwater culture system is both algal and heterotrophic bacteria 
>based
>(within the water column).  I was not a deliberate practitioner of
>greenwater culture, but it developed for a period of oh, I guess a month or
>so within my system, and I was pleased to see it as long as the DO2 was
>always O.K., which can be a challenge sometimes.
>
>Bottom line is I would wager that most aquaponics practioners on this list
>have mostly "clear water" systems, if that is a loose enough but 
>appropriate
>term....perhaps stained a bit with tannic acids, other Dissolved Organic
>Carbon species present from feeds and other inputs over time, and a bit of
>turbidity, but not much.
>
>Hope that helps.
>
>Tedzo.
>
> > O.k., so I assume since I got ZERO responses to my original post on this
> > subject (see below) that no one on this list does this... OR, was 
>everyone
> > just busy that day?...;-)
> >
> > Devon
>
>

_________________________________________________________________





| Message 18 

Subject: Herbicide
From:    marc 'at' aculink.net
Date:    Mon, 19 Mar 2001 12:20:47 -0700

Browsing through my workplaces news stories I found a very
interesting article.

Here's an interesting science story about an organic/natural
based
herbicide figured out by a teenager:

http://www.sciserv.org/sts/60sts/Kessans.asp

Marc N.






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