Im getting an eclipse catfish and wondering if there is anything I should know about it I looked up alot of stuff about and im going to get 1 in about 4 weeks .I know that they will sometimes stop growing if there in a small tank(petsmart has 5-10 in a 7 gallon and there small and they've been there for monthsand havnt grown)So I know all the basics.
If you follow the care/datasheets you have found on the fish, you will be fine.
It is an undemanding fish, an unfussy, greedy eater. If you get just one, it will most likely hide all day long. If you want to see it and bring the most interesting behavior in it, I'd recommend getting at least half a dozen, a dozen is better. They may fight/push each other around a bit but not anything vicious at all.
An adult usually reaches somewhere between 1' and 1.5'. So, according to the usual MINIMUM tank size rule (footprint 4xL by 2xL, where L is the fish's length), you would need an about 5'x2.5' footprint, which is, however, usually upped by 1.5 times for both tank length and width when it comes to an actively swimming fish like sun/eclipse catfishes.