Maybe I will just leave CYA alone for now. I missed Chem Geeks little nugget, CL as % of CYA. It really simplifies the relationship. I love this stuff!! I live in So. Fl. so I am considering starting a pool maintenance business and building it slowly, over time so as to offer the best possible service that I can. I want to set myself apart from all the run of the mill pool services out there. Who knows, eventually I may even reach "Pool Geek" status! : )