Just added CYA (via sock in skimmer method 3PM yesterday). I squeezed it every few hours to get it to dissolve faster and it was pretty much gone by this morning. I've since removed the sock and the pump is still running. I noticed the surface is covered in little white flakes, which I assume to be undissolved CYA. Is it safe to swim with those flakes still floating around? Not sure why they are not getting lodged in the cartridge filter, which I cleaned just before adding the CYA yesterday? It seems as if the flakes are just getting pumped through and back out through the jets.
All other chemicals are in balance and have been for months:
pH - 7.5
Chlorine - 4.0
CYA - 25 (before adding new stuff yesterday)
TA - 80
Calcium - 250
From other threads I've seen maybe it isn't CYA, some sort of calcium being produced? Or maybe windblown material? I did check around and it seems as if some other surfaces have some white flakes so maybe it is windblown. I also included a picture below. I just don't see how it could be CYA as this stuff must be getting caught in the filter... then windblown more of it so filter/pump can't keep up?