My friend from work has just given me the above tank. It has an under gravel filter with airstone and motor and I'll get a small heater for it. Can I keep one betta in this? The MTS has really kicked in !!! 
PS Does anyone know if there is a small algae eater which won't eat guppy fry? My fry tank has quite a build up of algae already.

PS Does anyone know if there is a small algae eater which won't eat guppy fry? My fry tank has quite a build up of algae already.