As everyone else has said- get a good test kit. Taylor 2006 is what I use. You can't go wrong with it. I like to keep my CYA around 60 and I do run my chlorine a little high- 8 to 10. With the Taylor testing kit and this site I have had a crystal clear pool for 3 1/2 years. Nothing but trouble before that using pool store test kits and their chemicals.