Asking for a friend.
20k gallon IG vinyl-lined pool with sand filter. Little Rock, AR area.
Since July (when temps climbed to 95+), he has been having a real problem keeping chlorine in the pool. He had an algae bloom but got rid of that with water back to clear. Added 2lbs of shock (Leslie's Power Powder Plus) at noon on 8/3. Checked levels at 10pm and FC was 2ppm, ph was 7.8, TA was 90, CH was 90, and CYA was 30. Took levels again 19 hours later, FC was 0 and other levels were the same. Question is why does his chlorine drop from 2ppm to 0ppm in 19 hours? Air temp was 100 degrees that day with water temp of 89 degrees. Is the high temps to blame for this?
Appreciate any info!