My pool turned green at the end of the summer and then I neglected it till three weeks ago. Thanks for everyone's posts on this site, this is the first time I've tried the SLAM method, I've been SLAMing for the past three weeks - and the pool is looks great now. The chlorine is now at 9 ppm. I'd love to just get the pool covered already, but want to make sure it's balanced first. Can I do an OTO PH test with chlorine at 9, or do I have to wait for the chlorine to go lower?