well, in a 1 gallon, i put guppy fry, yes it sounds quite cruel, but when you have other livebearers that have more fry, anything works! i also just put some native snails and a few plant leaves in there to see if i get anything good. if you had a undergravel filter, you could put 2 endlers in there, has to be stocked with plants though. i've seen this set up in action! but i still wouldnt recommended. if i had a spare, i'd just use it as an algae collecter...