Backyard Aquaponics
A place to discuss aquaponics

Hi all,

New to this i have a 1000ltr FT and 7 half blue barrels as GB but want to add a ST to go CHIFT PIST.But what size ST do i need and do i have to drill a hole in the FT to connect the SLO.

Thanks Fossil67

What sort of fish tank?

what happend to the other half of the blue barrell ????

Sump needs to be able to Hold enough water to fill all growbeds (filled with media) and still have the pump covered with some water in reserve. i have 3 barrels half buried, linked together.

I ran a 40mm SLO on my FT but if i had my time again... it would be bigger atleast 50mm through the tank into 90 to the beds.

Another tip dont go down to ground level and back up again keep it all on a down hill run.

Also dont put the drain in too high as the ft will overflow quickly due to restriction on outlet.....

have fun!!

Are you using flood and drain (siphon) or constant flood?

If flood and drain your sump will need to be large enough to hold total volume of water your growbeds should they all drain at the same time, plus some water to keep your pump submerged plus some to cope with evaporation.

I think a half barrel would hold about 40 litres of water once filled with media so 7 would give you 280 litres (can some correct that figure if I have it wrong). So with that I would suggest a 500 litre sump - more if you plan to expand.

In regards to the SLO. Go as big as you can. I use 90mm through the wall of my fish tank and all the way along my fence. I then have 25mm pipes (well 40mm which is immediately reduced to 25mm) for each Growbed coming off the 90mm SLO.

It is possible to do a no holes over flow (if you do a search you will find out how) but I think it would be easier to get some uniseals, drill a hole in your tank wall and push the pipe through.

Be careful with the no holes overflows. Get im right and they are fine but they can be really hard to get right and if they are not right then they are a whole put full of trouble.

no holes overflows can get gas and fail while you are away. I would only go there if you have some very strong reason for not drilling a hole.

Much easier to put in a uniseal and push the pipe through. So yes put a hole in the tank, and I would say put it lower than you think you need, you can always add some extra plumbing bits later if you want to set the water level higher but if you drill the hole too high well then it means you wind up having to drill another hole later after you learn the fact.

As to sump tank size, well if you are never going to add more grow beds (are these the 200 liter blue barrels? if so then each half is about 100 liters and to flood a bed with media I always just figure half though it is actually less but saying half actually gives you some extra leeway already in the calculation.) So 700 divide by 2 is about 350 and one must add a bit of extra depth for the pump (and a top up valve in my usual planning) so at least 450 so I agree a 500 liter sump would be adequate if you don't plan to expand.

However, I would say a 1000 liter fish tank needs 2000 liters of grow beds and a 1000 liter sump. So if you get an IBC to use as sump tank you will be able to expand your grow beds to allow for max aquaponic stocking. With only 700 liters of grow beds you will only be able to stock 25-35 fish once the system is cycled up.

And i bet you dident need mathmatics to prove it

Well I never did manage to prove it but I did gather a lot of evidence.