Different Calcium test results?

[tomreefer]

I checked my calcium levels with

Api -- I think actually API changed there kit it says CA2+ now anyway this reads 440 (What I was expecting)

Hanna showing 474 --- I am guessing this is perhaps need of calibration?

Can API actually be more accurate than Hanna? The Hanna kit is a pain in the butt if you ask me.

 

[bertoni]

Those are actually reasonable close, for hobbyist kits. The Hanna meter, if that's what you are using, has some issues with accuracy, according to a lot of reports. I would go with the API, personally, but both readings are acceptable.

 

[hkgar]

For calcium I prefer, and use, Salifert.