The "best" is which ever you have tried and has delivered good results for you. The comment about the roots rotting, to me is off. It's true they might do that in soil, but in a fully aquatic enviroment they do quite well.always4lora;5077283; said:Whats the best plant species to use? Any pothos? I had a quick google and it said the roots will rot if left in damp soil so reads as if they would rot in water :S