Thanks for the further advice and encouragement. We have had the filter running 24/7 and we are starting to see some improvement. I agree, I really think it is a combination of calcium and dead (or lingering live) algae. This afternoon my daughter said "Mom, why is the pool brush at the bottom of the pool?" I had no answer for that, but was thrilled that it could be SEEN at the bottom of the pool, even if "through a cloud". Couldn't see a thing a couple days ago.

Am continuing to test 3x a day; Cl is holding overnight and went down only slightly during the day today. We had a lot of rain yesterday and pH is 7.5 now.

My husband is no longer threatening to bring the John Deere home to smash it to pieces and we can (kind of) see something at the bottom, so we're making progress and all thanks to the Pool Forum!

Thanks so much!!!!