I did a full battery of tests on my pool water after testing FC/CC, pH and tA for the last few months. Here are the results other than FC/CC
TA 60 (need to raise it)
Calcium 170 (down from 270 late fall)
CYA ?? Less than 25 (I filled the water to the top of the tester and I could still kinda see the dot)
1. Why do I lose calcium? I started with almost no calcium back in October and was warned to be careful adding calcium because once you add it, it stays unless you drain the pool. so I raised it up to 270. Well I haven't drained the pool. We have had some rain and have probably added a couple inches from the tap. Where did it go? Is it normal to lose calcium?
2. How can I guess how much CYA I need? Should I assume I have 20 and add to raise it to 40? I'm in the Woodlands, TX if it helps.
Thanks for the help as always!