Well I guess I’ve spent myself into a dilemma. I’ve been testing with the API master reef kit and didn’t like comparing colors so I ordered a Hanna DKH kit and ran a test. It showed my DKH to be 6.5. Now just this morning my API kit showed 8 so I ran the Hanna test again and it showed 6.6. Now I’m using RO/DI water and Fritz blue box salt and my salinity is 1.025 using a refractometer and my Ph is 7.9 using a Ph meter. My Ca is 400 using the API kit Is this normal? What would you do?