API Calcium Test

[jlmawp]

My guess is that you precipitated calcium at some point.

I also use API for calc, alk, and pH. I test some newly mixed water (after several hours of mixing) with every new batch of salt. Yes, RC is lower than advertised for Ca and Mg, but not that low. Usually Ca is round 400 and MG in the 1200 range. I have contacted them about this and was told to use 3 different test kits to confirm, that my container could be leaching (absorbing Ca and MG??), and some other bogus excuse. I use turbo calc (calcium chloride) and Tech M to bring my change water up before adding it to the tank. Same thing you are doing with dosing after a water change, I just mix it into the change water so it is mixed before going into the tank at a higher concentration. I feel I am less liely to get precipitation this way. I don't know that it makes a difference.

Kim

Thanks for the advice. I never actually saw any precipitation, and I pay pretty close attention. I never ever went above 420 since I got the tank, but not testing for alk or mag may have been what got me.

I just ordered the Salifert mag/alk/calc test kits, so hopefully I can come back with some actual numbers in a week or two. This is one aspect of water chemistry that I never really wrapped my head around or paid a lot of attention to, so this is a good opportunity to do that.