> Do you recommend power heads over a simple air pump - or is there a certain > size tank were a power head becomes necessary ? In our tank, which is a heavily planted 55, we would not recommend a power head because you don't want to disturb the surface anymore than possible so that the plants can utilize the CO2 which would rapidly dissipate with more surface agitation. We also only have a minimum of air going into the HS-5 and our plants keep growing and reproducing! We do have fish in the tank and the HS-5 is only in the tank because I don't feel comfortable without some air with the fish being in the tank. Kaycy ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@majordomo.pobox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@majordomo.pobox.com. Search http://altavista.digital.com for "Apistogramma Mailing List Archives"!