Multi-parameter recovery field outcome
Free chlorine and total alkalinity recovered together in seven days
A documented weekly treatment moved free chlorine from 0 to 5 ppm and total alkalinity from 80 to 90 ppm while CYA and calcium hardness remained unchanged.
San Diego County, California · November 14 to November 21, 2025 (7 days)
- Free chlorine
- 0 ppm5 ppm
- Total alkalinity
- 80 ppm90 ppm
- pH
- 7.67.8
- CYA
- 190 ppm190 ppm
The situation
- No measurable free chlorine with total alkalinity below the pool's operating target.
Starting readings
- Free chlorine: 0 ppm
- pH: 7.6
- Total alkalinity: 80 ppm
- CYA: 190 ppm
- Calcium hardness: 820 ppm
Treatment recorded
- 1 US gallon of 12.5% liquid chlorine
- 2 pounds sodium bicarbonate
Follow-up readings
- Free chlorine: 5 ppm
- pH: 7.8
- Total alkalinity: 90 ppm
- CYA: 190 ppm
- Calcium hardness: 820 ppm
- The high CYA and calcium hardness readings remained part of the longer-term correction plan