i would say for a single 5 gallon bucket 10-30 l/h im useing a wisper60 air pump in my 10g rubbermade tub and it works great and i just got a 70 l/h air acticve air pump for my next setup and it so WAY over kill and its loud as hell i sould have jsut got 2-3 wisper 100s for less $$