so recently hook up my tank with apex. I been noticing that my pH goes from 7.8-7.9 sometimes to 8.05 but it never passed 8.2-8.3. I tried to dose kalk with ato before and that only keep it above 8.1 . My tank info is 50g cube with kessil 360w, one wp25 (on at 10am and off at 8pm), sump with swc...