I'd never thought about trying to capture rain water to refill the pool--that's a great idea! I'm always thankful when rain water gets in there because that's less crappy well water I have to add. I've never heard of a metal trap but I googled it, and that looks like something that could really help me out. We had our water tested not long ago. I should look at that report and see exactly what's in the water that causes it to be so cloudy. Maybe the metal trap would help to alleviate that problem. Meanwhile, I still haven't gotten my PH down or my FC up high enough to be a shock level. I'm probably too conservative with the chemicals because I'm always afraid of adding too much. This morning the numbers were: PH=7.8, FC=26, CC=.5, CYA=120. I added more bleach and more muriatic acid. I'll test again this afternoon and just before dark.