I very had a 13g tank for a while now with one guppy, one platy, andone molly in it. I bought a pleco from the store that was supposed to grow only four inches, which I read online is totally false and usually grow bigger. I bought algae wafers as well for him. When I took the pleco home, he wouldn't even swim out of his bag and just stuck to it. When he finally swam out, he went right to the filter and stuck to that, which is where he died 2 days later. In that time I tried to feed him wafers, cucumbers, peas, etc and he never even flinched. Stupid fish... I check all my water levels and everthings good. One thing I did notice when I bought him though was his belly had colors on it and looked sunken it. Idk how he would of starved in 2 days. I'm stumped......