I have a question regarding water replacement. Won't rain water help? We had a lot of rain in northern California this past spring. It rained 1 or 2 days every week for about 2 months. Maybe that is why my CYA is not that high (currently at 40) given the fact that the pool service used trichlor pucks in our pool for the past 1.5 years before I took over. Not knowing the effects of the pucks, I was using them too until I found this forum.