Backyard Aquaponics
A place to discuss aquaponics

Putting plants in my new system today, how much seasol should I use my tank is 1000L and I have 2 x 500L grow beds.
Do I add it daily ect ?

I cup initiall of the concentrate, then 1/2 a cup per month if you notice any plant problems. Once your system is fully cycled and full of large fish eating lots, seasol is not required any more really.

Thanks for the reply I have added the plants and seasol to the water. I only have 9 small gold fish in the system so far (1000L) untill I get some trout, should I add more fish?

Just noticed your location rain...
Was a nice spot where I was there 30+ years ago
good luck with your system
Try and use the KISS principle and all will be good

Most people suggest using the folair application when you have reduced fish stocks, or have just planted seedlings.
But as OO suggests once your system is cranking, should be no need, but if system is struggling, is a good time to give it a go also.
Folair application is on the back of the bottle, is something like:
Seasol, folair application (25mm in 8L)
This is the ratio for watering over the seedlings, not to add to your total system water...

Mix up in watering can, and pour over folage.


9 small gold fish aren't going to be giving much to 2 x 500L beds I would think, and will definitely need the seasol until more fish arrive.

I would normally think something like a ratio of 20-25 fish per grow bed.

However 1000L FT and 2x500L grow beds, I realise that the beds will overflow before the full 1000L gets in them, but the FT must still be low at that point, this will also be a factor for stocking level and fish species. Above numbers assumes plenty iof water. Size and growth rate of fish will also be a factor.

Are you sure it's a 1000L and not a 1500L tank?

Are you using Flood/Drain system?

It is a 1170 L tank and when the grow beds start overflowing the water level has only droped about 250mm. The tank is 600mm high.
I am using flood and drain 15min fill 45min drain.
I would like to put 75 trout in.

60cm tank height??? OOPS seems VERY low to me. And water level drops another 25cm when grow bed is full ,, so only 35cm deep water in fishtank. I don't like the sounds of that.
1170 litres gives you around a 34 kilo of fish max.

I'd be waiting for your bacteria to get populkated in the grow bed media and re-thinking the fish-tank depth.

1000L tank Darrel... with 1000L of filtration....

Wont support more then 30kg of fish... that's 30 full grown trout....

May be able to stock 50 fish... if you intend to eat them progressively from about 750gms onward...

And the depth of water will limit your stocking ability as well... as 30 odd 1kg fish will have to exist at times in about 50-60% of your 1000L tank.... and extract oxygen from the remainding water.. as Chappo points out....

Chappo, Darrels system is timer based.... with overflow standpipes... so water is returning to the fish tank as soon as the growbed flood level is reached... ala BYAP kit systems...

Additional aeration will be required...

Hi all just installed my new pump and measured the how far the tank drains at over flow point, it is 130mm below high tide.
The GB's start returning water through 4 x 6mm holes as soon as the pump kicks in. I have a 4 stone aerator in the system. So for about 5 min there is 470mm of water left in the tank.

Kewl... that covers the issue of water depth and aeration... still wouldn't push past about 30kg of fish biomass though... with the current filtration capacity...

And thats after a season or two of experience.