Water balance field outcome
LSI moved from +0.20 to +0.03 after measured treatment
A recorded 0.36-gallon acid treatment moved pH from 7.9 to 7.7 and LSI from +0.20 to +0.03 over six days.
San Diego County, California · April 30 to May 6, 2026 (6 days)
- LSI
- +0.20+0.03
- pH
- 7.97.7
- Free chlorine
- 5 ppm5 ppm
The situation
- Positive LSI with high calcium hardness and high CYA in an existing residential pool.
Starting readings
- pH: 7.9
- Free chlorine: 5 ppm
- Total alkalinity: 95 ppm
- CYA: 155 ppm
- Calcium hardness: 1,030 ppm
- Recorded LSI: +0.20
Treatment recorded
- 0.36 US gallons muriatic acid
- 0.5 US gallons liquid chlorine
- No drain or refill was recorded during the interval
Follow-up readings
- pH: 7.7
- Free chlorine: 5 ppm
- Recorded LSI: +0.03
- CYA and calcium hardness remained unchanged and continued to shape the long-term water-balance plan