Backyard Aquaponics
A place to discuss aquaponics

I thought that I would post my current idea.
Because of the remodeling at the store in will be a while before I can start on this.

The fish tank will be in an existing building, a 16'x18' (4.8m x 5.4m) car garage built in the 1920's for model Ts.
1000 Gal. (3785L) Fish tank(poly stock tank).I can get it locally, my cousin owns a farm supply store.
Two 4' x 25' (1.2m x 7.6m) grow beds in 20' x 30' (6m x 9m) greenhouse.
FT will be maybe 12” (300cm) below the bottom of the grow beds so maybe I can use gravity for return.
How big a pump do I need and should I cascade the Gbs and fill only one at a time?
What should I start with for number of fish (Tilapia)?

Hope the metric conversions are close.

I have room for two setups this large. I was going to build one and see if it would cover my needs and if not I could add to it later.

I will be setting up a small system to figure things out. I will put up some pics when I start.

Ron

if you wish to 'Cascade' then you will need the GBs at different heights, the top of one being below the bottom of the other.

try to move 1000Gal/hr
each gb is approx 30 sqft
so trusting they're to be 1ft deep, you have 30 cubic feet per gb or approx 225 Gal.

so in total you have 450 Gal of GB and 1000Gal of FT

being that after gravel is added the GB will only hold about half their volume in water, total GB water volume is 225 Gal.
225 Gal is not a lot of water from 1000 Gal.
So I would suggest just fill the GB simultaneously and have then autosiphon into the FT.

Of course, this means every flood cycle you're FT will drop in level by about 25%

As a lot of us don't like that, we add a sump, and have the FT above the GB.
Do a search on CHIFT PIST.

KP I think the growbed volume is 4' x 25' x 1' x 2 beds = 200 cubic feet gravel = 1500 gallons x 40% water to gravel ratio = 600 gallons water to flood the beds?

Oh I guess you said fill them one at a time so yeah 300 gallons out of the sump. Sorry I'm going home now...

No, you are right... crap... damn converting to metric and back!

200 cubic feet is correct.

so 600 Gal to fill both beds is also correct.

I would still fill them simultaneously, as the height difference needed for cascading is not feasible in a GH.

Of course, a clever timer with 2 pumps would work well...

By clever I mean a HPM or other generic timer, with a relay set up so power is always on on of the two pumps but never both at the same time.
I can include a small diagram if you want to build one. I have it here somewhere, on another thread somewhere.