For at least the past year, I've noticed that my calcium hardness level never changes. It's always at 275. Over the summer I went through a 25lb bucket of cal hypo hoping to get my CH level up a little. But at the end it was the same - 275. I haven't tested my CH in the past few months, but today I tested and again it's at 275. Any thoughts as to what might be going on? I'm wondering if I have bad reagents.