Calcium Issues.

[MizTanks]

Parameters=PH 8.2~KH 9~SG 1.026~Cal when tested using API reads dark purple on 24 and then dark blue on 25 which tells me it's at 500. I'm not sure why my Cal is so high when the KH is in the acceptable range, although on the high end.
Could the fact that the tank's in my air conditioned room have an effect?

[XSiVE]

are you adding ca and alk at all or just through water changes?

a few points...

Ca and Alk aren't always consumed at the same rate typically it is close but not always... thus the reason a lot of people dose 2-part.

Your magnesium level may be low. without adequate Mg levels in the water, ca and alk can be unpredictable.

[MizTanks]

I use no additives at all. I test my make up water and the Cal is always 420-PH 8.4-KH 7-SG 1.025-Salinity 35 after 24hrs with a power head.
For some reason my Cal is running high in my tank???
I refuse to pay 40$ for a mag test kit and our LFS doesn't have one either, go figure :/