Using our Taylor K-2006 Test kit and testing the water every morning, we have had wonderful crystal clear water! Our cya is 45, so the desired chlorine range per pool math is 4-8ppm. We have never been below 4, and I use the pool math calculations to maintain it at 7. I brush and vacuum the pool at least once a week. On the 3rd or 4th day after brushing or vacuuming, I will notice a slight greenish covering on the sides and bottom, but only in a few places - not the entire pool. I brush that away, little green clouds form but quickly dissipate - the water still remains very clear. Is this algae I am brushing away? Is that to be expected? We have an 18,000 gallon inground vinyl liner pool, and it has been very sunny, hot and humid here in Maryland. Our 14th day of 90+ temps. My chlorine test readings are pretty consistent each morning at 4.5ppm, dropping from the desired 7 after 24 hours. I've occasionally checked our overnight loss, and it is 1ppm or less. Should I be concerned I've got an algae problem and perform a SLAM? or is a little algae to be expected, and keeping the chlorine levels within the suggested range is all that is needed to take care of that little bit? Thanks for your time! Kathy