My housemate and I are starting out keeping fish and are starting simple; 48gal tank, aiming for three fancy goldfish (a moor and two of either fan or butterfly tails).
Thing is, someone’s advised that corys can be kept with goldfish and my housemate is smitten with the idea, but I’m not sure we have the tank size for an appropriate school of corydoras (we’d need six, as far as I can tell) as well as the three fancies. The tank is roughly 4x1x1.5 feet (lowballing it slightly, but that’s okay), and I worry that while it’ll all seem well and good while the fancies are small, they’ll grow and so will the corys, and we won’t have enough room and also won’t be able to keep up with the bio load of so many fish.
This isn’t something I’ve been able to work out with any online calculators; does anyone have any advice on whether it’s possible at all to keep corys with fancies in a tank this size while still having enough corys that they can school? And if not, a proper explanation would probably help me explain why not to my housemate. Thanks for your help!
There's no issue with the tank size, but it is inadvisable to keep cories with goldfish because when the goldfish are big enough they will try to eat them. The cory will put out its defensive spikes and the result is that the cory will be jammed in the goldfish's mouth, very difficult to remove, and will end up with a dead cory and a goldfish with a damaged mouth/throat. We've seen this happen repeatedly and it really isn't worth the risk of this happening.