I had to add CYA this year for the first time-tested at zero at opening and added to get to 30- This had been fine since we've had little sunshine and swimming up til now. I got my FC to 6 last night and today 4 people swam and it was sunny. I just checked my FC and it was 2. I'm thinking I may need to add CYA to get to around the 40-50 range. Last year had to drain and fill to get rid on CYA so I'm leary of adding too much-should I leave well enough alone? My pool is crystal clear and ph is 7.5 but my TA is hign (190).