I recently got an aquarium from an acquaintance of mine. She and her husband robbed a store and went to jail, she had her mom call me and tell me that I could have her fish if I'd find a good home for her cat (I'm allergic). I used to babysit for her, and always admired her fish. I know very little about any other fish than goldfish, though. When I got the tank there were two zebra fish, two angel fish, and a common pleco. The angel fish didn't survive the move to my house I bought two goldfish, and put them in there. One since disappeared. Literally, went *poof*. I figure that the pleco ate him, cause he's the only one big enough to make a fish poof like that, so I started doing some research, and now I'm concerned that maybe I'm not feeding him enough. I read that you can feed them cabbage or lettuce, but I'm wondering do I need to cook them, first? And should I supplement with something that won't make it want to eat my other fish. Honestly, I really like him, and want him to be healthy and happy. I'm not sure the size of my tank, it's big. I think it's a 50 gallon, but I wouldn't swear to that. It has part of a lid, enough to keep any of them from jumping out, but the light is missing. It's a freshwater tank, and I keep it at room temperature. I buy distilled water at the store, and put about a gallon a week in the water. I'm not sure what kind of filter I have, but the water stays clear so I'm assuming it works fine. Oh, that reminds me of another question. Why do I keep getting bubbles on the top of the water?