Backyard Aquaponics
A place to discuss aquaponics

OK, set-up is going to be 2 x 3kL FTs, with 4 x 540L GBs per FT (2.16kL).
FT's are 1.8 diameter 1.2 deep.
GBs will be over 50% hydroton, rest scoria.
I've had a look, and can't find the thread that describes how much volume the media displaces in a GB.
My concern is lowered water levels on pump cycles, and I'm wondering if the tanks should be joined to make a quasi 6kL tank.
BTW, the space in between is access, and needs to be walked over, hence two loops in the siphon.
Also, the pumps would be run alternately.

so you are looking at 6000L FT (total) with 2160L GB (total)

This would mean a low fish stocking rate because you won't have a lot of growbed.

Media usually takes up between 40%-50% of the volume of the bed. I don't think low water levels will be the problem.

Hi Uncle. Approx rule of thumb is 40% water displacement in ur pump cycle. Max round figures of about 850 litres out of ur fishtank at the height of ur pumping cycle, leaving lotsa water in the fishtanktank.

If ur running 2 pumps, keep the systems separate. Your pumps need to be located in the centre of the tank. This is where the solids will gather, (least pressure) and where ur pump needs to be to efficiently pump them out.

I vote for keeping the tanks seperate, running seperate pumps (and aerators), to seperate growbed systems.

Any disaster should be limited to one system.

Also you can keep seperate species, and alter the pumping cycles to adjust your water temps to the need of the specific fish requirements.

Dont have your pumps sitting on the bottom if you can help it. If the water dissapears somewhere there is still some for the fish. The pump will usually not be hurt, they lose suction before they are completely out of the water. (been there done that )

Jaymie,
8 growbeds in total, 4230L (yes, yes, if it was built I'd have photos!)
TT,
So we're talking ~1kL (~50% of 2160L) out of a 3kL tank at MAX emptying - sounds quite manageable.
OBO,
Thanks, had thought about the quarantine/diversity issue, but temperature was an aspect I hadn't considered for species diversity much. I suppose that would go for plants as well.

oops, I missed the "per FT" bit

If you are already planning two separate pumps then there is very little reason to connect the two systems together. About the only reason I'm thinking of is for cycling purposes, using your first batch of fish in one tank to help cycle all the media in both systems but this is not a very compelling argument. Just keep the systems separate and fishless cycle. Then once you add fish into the first system you can keep plants growing in the second one with fishless means untill ready for fish in both.

hehe 'fishless means'