Pool backwash reduction at Wapato Municipal Swimming Pool
Pool backwash reduction was the aim at Wapato Municipal Swimming Pool, a 375,000-US-gallon pool in Washington operated by Yakama Nation Youth Activities. Its diatomaceous earth filters were backwashed often, which used up filter media, while chlorine and other chemicals added steadily to the running cost and the operator wanted clearer water for swimmers. One HydroFLOW® P160 was installed on the 6-inch circulation line serving the filters, and chemical and filter-media use were compared with operation when the unit was off. Backwashing fell by 65%, chlorine use halved from 30 to 15 buckets a month, and filter media fell from 60 to 20 bags a season.
The Challenge
- Pool backwash reduction was needed because frequent backwashing used up filter media
- Filter media use ran at 60 bags of Dicalite per four-month season
- Chlorine use was 30 buckets a month
- Acid, shock and stabiliser added to the chemical bill
- The operator wanted clearer water for swimmers
The Solution
- Unit installed: one HydroFLOW® P160
- Installation point: 6-inch circulation line serving the diatomaceous earth filter
- Pool volume: 375,000 US gallons
- Comparison: chemical and filter-media use with the unit on and off
For pool backwash reduction without changing the filtration system, the P160 went on the 6-inch circulation line that feeds the diatomaceous earth filter. Backwash frequency and the use of chlorine, acid, shock, stabiliser and filter media were then compared with the pool’s operation when the unit was off. Through the season, staff kept reducing dosing to hold pH between 7.2 and 8.0 and chlorine at 1.0 ppm.
