What could be increasing my calcium?

[Shnetts]

Looking to get some insight from someone who knows a lot more about reef chemistry than I do.

In one of my tanks my calcium is constantly 500-550. I use Red Sea that mixes to 450. I have tested freshly mixed water and it does come out to 450 +- 20. The tank is a 20 gal. The only filtration is a uv sterilizer, besides that I rely on secham matrix as my substrate.

 

[BryanM]

Are you dosing anything?

 

[Shnetts]

Are you dosing anything?

No

 

[Randy Holmes-Farley Verified Community Expert]

Then it is likely test error, assuming you are not using tap water, which can contain a lot of calcium.

 

[Shnetts]

Then it is likely test error, assuming you are not using tap water, which can contain a lot of calcium.

Is there something in particular that could be causing skewed results? I repeatedly get 500+

 

[Randy Holmes-Farley Verified Community Expert]

Is there something in particular that could be causing skewed results? I repeatedly get 500+

Might be a bad test kit. Have you tried it on new salt water?