I have a 5 1/2 gallon tank with a betta. When I had him in my 29 gallon, he seemed afraid of the gourami and black tetras I had in there. Now that he is by himself though, I am looking at his tank and wondering if I shouldn't get a small bottom feeder to share it with him. The tank is developing some ugly brown algae, so I thought of getting an algae eater, but it isnt' for maintanence; I can always just scrape algae off the sides of a five gallon (not fun, but doable) so that isn't really the problem, I'd just like another fish. Otos I heard to better in groups. I thought it would be neat to have a small catfish or something. Are there any bottom feeders that are small enough to share a 5 1/2 gallon with a betta, and also relatively non-aggressive? Or is that just too small for more than one fish?