Hi, we are thinking of getting fish for the garden. I heard you can keep gold fish in a water butt. We have a normal sized (210 litres) as well as a smaller. Would this actually work? It seems to me a water butt is deep but not wide - would fish have enough space? Our water butt is next to a fence, so it shouldn't overheat. I am happy to add plants, filtration and aeration as needed if this makes fish a possibility - but I though gold fish become very big??? I could have gold fish in a water butt if I'd have to rehome them after a few month... Are there any better alternatives or does it really only work with a proper pond? What about rice fish? Could we have them as long as we secure a metal crate or similar over the water butt?