My calcium is at 361 ppm and alk is at 8.1 dkh, these are currently the only Hannah checkers I own and don’t have a phosphate reader and I know most people don’t like API but it’s currently what I have till I can get mor checkers. Waiting for a sale but ph is a little above 8 from the color. Nitrite 0.0 nitrate about 10 ppm and ammonia looked like 0 but I was wondering how could I get the calcium up without hurting the alkalinity, I read these aren’t dangerously low but I would like to get Calcium up with out lowering alk. Is there a product I add or water changes? I recently did a 20% last week thank you