I have a problem with high levels of CYA, and I believe this is why I also have a problem with green algae. My CYA averages 80ppm which I have down from a high of 170. All my readings are in the normal range, PH 7.5, Alk 112, Calcium Hardness 270, average pool temp 82. Please note I live in a rain forest the water here is very soft and very clean, I average 100 pounds a month of calcium chloride just to keep my calcium hardness above 250, for a plaster pool. I've been keeping my FC between 2 and 4 with the average about 2.7, I want to know if I should keep my FC higher. I read somewhere on this forum a chart that gave FC averages based on CYA but I can't find it again. Any help will be greatly appreciated.