Hi guys . Just set up my evo 13.5 about 2 months ago 1 inch araganite bed plus 8lb life rock and put marinepure gems in filter chamber (gems were in my 75g DT for 4 months ) . Ph was very low 7.6 - 7.8 so i buffered with seachem reef buffer . this happened several times over 1 week. just tested dkh and was at 20+ dkh !!!!!!!!!!!!! (hanna checker i didn"t belive it tested it against my DT hanna checker read 11.7 dkh so i kNow its calabrated ). Did a 4 gal water change brought it down to 17.5 dkh I plan on doing another water change . ph DROPPED AGAIN to 7.8 . I have since stopped using buffer for adjustments. WHY is ph staying so low with such high alk !!