I have a 20 gallon tank with 4 plain old comet goldfish. Just your basic tank. I'd love to have a fancy one, but I'm up against a spouse who thinks fish tanks are silly. He thinks they are pretty, but says they're too much trouble to mess with. My parents and sister have really nice tanks and fish ponds. My sister gave me her fish pond when she upgraded but my husband won't let me put it in the ground...GRRR!!! Some people just don't get it. But anyway, I'm not very adept at my tank and my fishes sometimes pay the price for that. I was hoping to be able to get some advise here so that my tank looks nice and I don't kill any(more) fish. My kids LOVE the tank (7 and 3) and have named all the fish, so it's something I can do with them and hopefully pass the love of keeping fish off onto them like my parents did for me and my sister.