i think it kinda depends on how bad your algae is. you dont want alot, cause then you will have to feed them algae if they clean your tank out. and the waste they excrete sinks right to the sand and cause more algae if you dont clean it up.I would add a couple at a time and see how much they can consume. i got 2 in my 60 gal and they keep up pretty good. just my opinion |