dog, Sounds like you're using a DPD test for chlorine which is difficult to get good results from with high levels of chlorine (over 5 ppm), which I'm pretty sure you have.

That's probably also the problem with your calcium test; the high levels of chlorine are bleaching out the hardness indicator.

I wouldn't worry about the calcium hardness for right now (until your chlorine comes down to sub 5 ppm). Keep monitoring your chlorine levels with what you have or get a pool store that uses FAS-DPD testing to test your water.

You'll really need think about getting an FAS-DPD chlorine test if you're going to do this yourself. Ben's PS234 and the Taylor K-2006 both fit the bill.