Thanks Kypros, now that's cool; the part about using the filter as a co2 diffuser, I wouldn't have thought of that; my dr foster and smith automatic co2 system came with a reactor and its own pump and etc; I need to be careful though with sizing my recirc pump though since I will already have two Marineland c360 canisters flowing at a total of 360 gph each plus my wet/dry pump running at about 200 gph; that's 920 gallons per hour which is almost 4 complete cycles of the tank per hour; Does anyone have an opinion on what too much circulation would be for a 260 gallon tank? I want my fish to be healthy and strong in addition to great plants but I don't want to overstress the fish with too much current! Thanks for all your help, Jeff. _______________________________________________ GSAS-Member mailing list GSAS-Member@thekrib.com http://lists.thekrib.com/mailman/listinfo/gsas-member