Pool Turnover Rate and Chlorine Demand
Required pump flow from pool volume and turnover target.
Example
You enter
- Pool volume (gal) 20000
- Turnover target (hr) 6
- Free-chlorine target (ppm) 2
- Chlorine product cal_hypo
You get
- Required pump flow 55.6 GPM
- Dose pure (lb) 0.3336
- Chlorine product to dose 0.5132
Checked against published worked examples from: NSPF.
Details, formula, and sources
ScopeRequired pump flow from pool volume and turnover target, plus the chlorine product to dose a free-chlorine target (cal-hypo / trichlor / liquid bleach). Per the NSPF CPO Handbook and ANSI/APSP/ICC 11.
Formula or tableRequired flow (GPM) = pool volume / (turnover hours x 60). Chlorine product (lb) = volume x ppm x 8.34 / 1,000,000 / available-chlorine fraction (cal-hypo 0.65, trichlor 0.90, liquid bleach 0.125).
Source and editionNSPF Certified Pool Operator Handbook (2022); ANSI/APSP/ICC 11 (Public Pools and Spas).
Free accessphta.org for the APSP-11 TOC; NSPF handbook licensed.
What governsEstimate. Operator of record and primacy agency govern.
API field namespool_volume_gal, turnover_hr, chlorine_ppm, chlorine_type, turnover_gpm, dose_pure_lb, chlorine_product_lb
- Water weight 8.34 lb/galphysical fact for water
- Turnover default 6 hr commercial / 8 hr residentialNSPF / APSP-11 typical
- Available chlorine cal-hypo 65% / trichlor 90% / liquid bleach 12.5%NSPF Certified Pool Operator Handbook