Thanks for the input Janet. As I say, things are clearing up nicely so not worried at this point. I will just do the Borax thing for now and backwash the filter as necessary. Threw the solar cover on and turned on the heater this morning as the kids are getting anxious to swim, even though the water is only 50 degrees! I have a heat pump so will take a few days to get the water even close to swimming temp. although we are expecting warmer weather through the week so I am guessing the kids will jump in on Thursday or Friday, even though it likely will not be warm enough for me.