Our pool has gone from crystal blue to green and cloudy. We have a 20k gallon, gunite pool with pebble finish and attached spa that was installed last year. We have had incredible pollen this past month in Massachusetts and I am not sure if the pool just couldn't handle it. It was opened by a professional and turned lovely, clear blue in just days. I have added salt a couple of times but now realize it is hard to get good salt readings without consistent temps above 70 degrees. Our numbers have been fine, just needing to add Acid periodically with the SWG. I added 2 1/2 gallons shock today and just completed a 24 hour boost. Started running the filter 24 hours a day. I'll check the numbers in the morning again. My question is, how do I know if this is algae or just the result of pollen? The filter was a mess after only three weeks when backwashed yesterday. I'll do it again tomorrow. Any thoughts are appreciated.