Enter pool volume, turnover target and pipe run to get required flow rate, pump kW and recommended pipe diameter.
For residential pools, water should turn over completely every 6–8 hours. Commercial and public pools require more frequent turnover: 4 hours is common. Spas and hot tubs should turn over every 30 minutes due to higher bather loads.
For a 50 kL pool with an 8-hour turnover, you need 6.25 m³/hr (104 L/min) flow. With a 15m pipe run and filter, the pump needs around 0.2–0.3 kW. A typical 0.37 kW (0.5 HP) variable-speed pump is suitable. This calculator provides exact figures for your pipe run.
Variable-speed pumps reduce energy consumption by 40–70% compared to single-speed pumps. Running at lower speeds for longer periods is more efficient than short high-speed cycles. The higher purchase price is typically recovered in 2–4 years through electricity savings.