Im running a sunsun 370 canister with UV light on , with bio balls , ceramic tubes, phosguard by fluval and mechanical filter sponge( blue one ) and polishing pad. White one. Temp is 77, using quantum sps and mixing to the instructions gives you alk around 8 and ph at 8.3 cal 410-420 mag 1250-1300. Ive done multiple 25% water changes and my alk is still at almost 12. Is there something i should be checking besides water? 2 corals already died and im stafting to wonder . I have 4 fish and clove polys, and a mushroom and a goni which all look fine. Tips appreciated thx