Hi. I've had the pool for 4 summers and never had a problem until this year. It's ~10K white fiberglass, with a sand filter & PoolFrog mineral system. This year I cleaned it up and got it started with my typically beautiful sparkling, clear blue water. After about two weeks, it turned green but still very clear. I tested with my small kit several times & always came back with good results. Took a sample to the pool store and they said it was balanced, but the Phosphates were high & Calcium was low. Per their instructions, I added 5 lbs. of calcium waited 1 hour then 1 bottle of phosphate remover. Within 30 minutes the water looked like blue milk. After almost 2 weeks, the water is slightly less milky and has a blue-green tint. I purchased the K2006 kit and tested yesterday. My readings were:
CYA - the black dot disappeared when the level was only about 1/3 of the way to the 100 mark.
What do I do first? Drain and replace the water?