Calcium testing

[AdamSabina]

Dose 66ml of calcium chloride a day. But lately BOTH of my testers are failing me I think. They both used to read within 20-30 ppm of each other. My salifert thinks my calcium is at 280 and Hanna check say 580... ***. I haven't changed my dosing, salt mix, or added any corals. Visually every coral is happy right now. I had to re-read the direction and RETEST two more times with both!!! I admit 580 is more likely than 280.

 

[bertoni]

The 280 ppm sounds very wrong to me. I'd get a third opinion, though. Testing is a constant source of trouble. Kits do tend to drift over time as the reagents lose water and become more concentrated, for example.