Can someone recommend a good home test kit? I'm particularly looking for something that tests CYA. My understanding is that with an SWG we should have our CYA at 60-80. When we have taken water to 2 different pool stores their tests only go up to 30 or 40! I've learned more on these forums in 2 days then the weeks of banging my head against the wall with these pool stores. "CYA? That's not important." Really?