Skip to main content
188+ Google ReviewsCPO Licensed · C-10537740+ Years
Pillar guide · 10 articles

Pool Hydraulics: Turnover, TDH, and Keeping Water Moving

Every chemistry problem, cloudy pool, and equipment failure eventually traces back to flow. If water isn't moving through the filter and chemical feeders at the right rate, nothing else works. This pillar is the hydraulic foundation.

Every chemistry problem, cloudy pool, and equipment failure eventually traces back to flow. If water isn't moving at the right rate through the filter and chemical feeders, nothing else in the pool operates correctly. This pillar is the hydraulic foundation.

The turnover math

Turnover rate (hrs) = Pool volume (gal) ÷ (Flow rate gpm × 60)

Code-required turnovers by pool type (minimum):

  • Residential pools: 6–8 hours
  • Public/commercial pools: 6 hours
  • Wading pools: 1–2 hours
  • Spas: 30 minutes
  • Splash pads: 30 minutes or less

Four turnovers filters approximately 98% of the water. More than that is diminishing returns. Fewer than that is a water-quality bomb waiting to detonate.

What operators actually need to know

  • How to measure actual flow vs. designed flow
  • Total dynamic head and pump curves
  • How to spot and stop cavitation before it destroys an impeller
  • VGB Act compliance and dual-drain configurations
  • Surface-water removal and why skimmers/gutters do 80% of the cleaning

Guides in this pillar

Pool Hydraulics & Circulation · Article 1 of 10

All guides in Pool Hydraulics & Circulation

Related pillars

Keep exploring

Want a pro to handle all of this for you?

Our CPO-certified techs run this exact playbook on every weekly service visit.