Split off of it's original topic, as it was off topic for the original post. JasonLion
I know this is an older post, but I have to take exception to the belief that algae cannot grow with FC at 3. I'm a pool service professional in South Florida which arguably is the toughest environment in the US. Algae can grow with FC at 3. I came across two pools just today with algae present and FC at 3+.