Backyard Aquaponics
A place to discuss aquaponics

Good Afternoon All, I am writing to find out from someone in the know-how I can transform my 3000-litre fish tank into a sustainable aquaponic setup.
My fish tank is outside and it wraps around the outside deck of my house, so I am limited with what functions I can do.

Can easily be done with a pump, some pipes and about 6000 L of growbed/s

Have a read of the IBC of aquaponics for some ideas about basic setup if you haven't already.

Suggest giving more details of your fish tank... Maybe even photos. What sort of growbeds are you considering?

It's hard to give advice without knowing a bit more.

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From the two pics I have sent I will give you the dimensions of the pond. 500x500x21 metres.
I have fish approximately 30 but that can fluctuate depending on egrets around the area, that is why I have glass over sections of the pond along with some plastic blow-up balls to deter them.

Very nice. Wish I could have a setup like that.

Algae might be a problem... most of us have our fish tanks shaded. But I imagine that you have already dealt with that with your existing setup.

How important will it be for you to maintain visual aesthetics? This will impact on the type of growbeds or DWC that you have. Or you could even float some more plants on top of your fish tank.

Have you read enough to understand the basics of cycling, ratio of growbed to fish tank. ratio of fish load to water volume and growbe.

Have you considered if you will have a syphon or constant flow in growbeds if not doing DWC?

What sort of fish are you wanting to keep... ie continue with whatever you have at the moment (why don't you let us know what they are). or do you want to eat the fish (could be trout but silver perch are probably easiest in Geelong).


All of these things are well covered in this forum and best understood before setting up.

Thanks, Dave, I have goldfish and some koi and I was thinking of setting something up on the shaded area of the pond refer to where the yellow ball is as that only gets morning filtered sun. In the afternoon it is completely shaded.
I am happy to give the goldies the flick but since I have had them for 10 years I think that maybe a little harsh. Would silver perch eat the goldies?.
from the pic with the yellow ball I have two submerged pumps, one is for the fountains in the pond the other is pumping water to a gravity-fed filter which has been working constantly for 13 years ( oase pumps are sensational).
The pond I occasionally fill with tank water to top up or it gets topped up with the overflow off the glass roof which is positioned above the pond (refer to another pic). The ph appears ok as the water lilies are growing ok and I haven't had a dead fish for a number of years.

Silver perch are omnivores but unlikely to eat the goldies I think... I can't say for sure but others on here will know.

SP are slow growers... particularly in your winter which is colder than mine. They will just about stop eating. But they're tough. I ordered twice as many as I needed with my very first batch assuming many would die... but they all survived so I was overstocked and had high nitrates (not as much of a problem as some suggest - at least not for me anyway).

They taste great smoked... I'm just about to dispatch and smoke another couple of jade perch (very similar to SP and faster growers... but won't like the cold of Geelong)

Still not sure how you want the growbeds to look. IBC is cheap and functional... easy to drill etc etc. I have adapted rainwater tanks - looks a lot nicer but trickier to plumb (at least it was for me because I had no skills when I started). Or maybe you will stick with timber to match your deck.

if you have 6000 L of growbeds and 3000 L of water, you could have a lot of fish (and plants). But you'd be better off starting out stocking less agressively.

Some rules of thumb which are well covered in lots of posts on the forum:
try to turn over your fish tank water through your growbeds at least once an hour
at least 20 L of wet media for every 500 grams of adult fish - ideally 25 - 30 L and even more is safer.

your system is already cycled and you probably know all about that already... adding lots of media (gravel or clay balls?) shouldn't be a problem because your water and existing filter are full of the right bacteria already. but we still don't know if you want to do DWC or growbeds)

I have no experience of egret trouble... but I think you might end up having to cover the tank a bit better... a nice big silver perch may be tempting target for them.

Suggest come back to us with your vision in a bit more detail... maybe even a sketch... let us know if you plan constant flood or will have a syphon (remembering you can do DWC). If using syphon, consider if you will need/have space for a sump tank.

Wow! looks nice.

Thank you, all I have to do is change this so that I can grow veggies and more fish!.