Backyard Aquaponics
A place to discuss aquaponics

I currently have 2 systems running , one using an IBC and the other using one of Murray's balcony kits. As with most APers I am pretty much constantly looking at how to "do more" , ie the bug to add more to the overall system has to be balanced by not spending too many $$$.

Looking around at tanks and getting a 2500lt (nominal volume) poly rainwater tank is pretty simple and relatively cheap $500ish. Getting a "fish tank" of similar volume seems to start at well over the $1000 mark.

Are there any experiences good and bad to using one of these polytanks as a fish tank, or am I just barking mad ?

rgds DJ

one of the Scott's (sorry too many names ) in Sydney uses a rain tank

Only challenge I see with rain water tanks as fish tanks might be the lack of access or needing to cut the top off the tank. Some rain water tanks are probably also deeper than they are wide so might make netting fish out pretty challenging.

Just make sure that the tank will still be structurally sound if you cut the top off.

If you can sort out the height issues and make sure you can plumb though the tank as you would need for the purposes of AP then it might be worth looking into.

In theory any round tank should remain quite strong after the top is cut off simply because the water inside is pushing evenly outwards. A square or retangular tank is going to have its sides bow and wouldn't work.
I considered a 3000l rainwater tank cut down to 1m high to leave approx 1500l but then I came across an aquaculture tank with a sloping bottom for next to nothing. So long as you set the tank up to either pump or overflow from the bottom then any round poly tank would be good. Although a cut rainwater tank may flex when you lean on it IMO it will still serve you well.

I wonder if poly rainwater tanks floor would become coned if it was sat on a special stand. My swirl filter does not look like a special tank. It just sits on wedges. And if you cut the top off you might be able to make a GB out of it.

Check out mizzie system ballarat it uses 2, 3000 litre tanks 6 foot high sorry 3

here viewtopic.php?f=18&t=3690&start=75

apart from the plastic tanks you can always use old gal ones

I use a rectangular poly tank dug into the ground with 2 access holes cut into the top, about 1600 litres. Round tanks are a hell of alot cheeper. No problems, poly is good.