Hi all, I'm volunteering to help fix up a neglected tank at a local nursing home. Shouldn't be that hard, except it's a custom built tank. It's 20 gallons but really wide...made to look like a wall-mounted flat screen tv. There are hidden compartments on either side of the tank for filters and heaters. What do you call this system? I thought it might be a sump but after reading up on them I don't think that's what it is.... They currently have some little Top Fin filter running in there, but it looks like there is all kind of media and a motor they aren't using. I'm inclined to replace what's in there with something I know will work, but I'm not sure what kind of filter is best for such a compartment. Could I use a regular canister filter? Sorry for the vagueness of this post...hopefully someone will know what I'm talking about.