Somebody had told me that with pool heaters, the FC should not go above 5ppm. I have looked online and not found anything to prove/disprove this. My chemicals are currently FC 3.0 CC 0.0 TA 90 CH 290 CYA 50 Ph 7.4 Borates 30 Water Temp 82. According to the pool calculator, I should be at at least 4 and could go as high as 8ppm. Can I do any damage to the heater if I go up to 8ppm?