DENITRATOR filter it is known to lower ph! no co2 used i have 4 wave makers 1400 gph, 1250 sump pump, chiller 1/3 hp, ESHOPPS S-200 in sump protein skimmer, PH CONTROLLER & ORP MONITOR. 12000 WATT BACK UP GEN, ATF,AUTO FEEDER, TWO TEMP CONTROLLERS HEATERS & CHILLER. SORRY FOR NOT BEING CLEAR ON...