Free Pond Pump Calculator - GPH/LPH Flow Rate | Pond Calculator
Free pond pump flow rate calculator. Calculate recommended GPH/LPH based on pond volume and turnover rate for optimal water circulation.
How to Use the Pump Flow Rate Calculator
Enter pond volume (gallons) and turnovers per hour to calculate the minimum pump flow rate (GPH). Generally, 1 full turnover per hour is recommended.
Koi ponds typically need 1-2 turnovers per hour, while water garden ponds need 0.5-1. Add extra flow for waterfalls or fountains.
Consider the actual head height when selecting a pump. Effective flow rate decreases as the water is pumped higher.
FAQ
How many times per hour should pond water turn over?
For koi ponds: 1–2 turnovers per hour. For water garden ponds with few fish: 0.5–1 turnover per hour. For heavily stocked ponds: 2+ turnovers per hour. More fish = more filtration = higher flow rate needed.
What is head height and how does it affect pump selection?
Head height is the vertical distance water must be pumped. Every foot of head reduces pump flow by 10–20%. A pump rated at 1,000 GPH at 0 head may only deliver 600 GPH at 5 feet of head. Always check the pump's head curve.
Should I run my pond pump 24/7?
Yes, for koi ponds the pump should run continuously. Stopping the pump even for a few hours can deplete oxygen and allow ammonia to build up, stressing or killing fish. For water gardens without fish, you can run the pump 12–16 hours/day.
What size pump do I need for a 1,000-gallon koi pond?
For 1 turnover/hour: 1,000 GPH pump. For 2 turnovers/hour: 2,000 GPH pump. Add extra capacity for waterfalls or fountains. Always choose a pump with adjustable flow rate for flexibility.
How do I reduce pump energy costs?
Use an energy-efficient DC pump instead of AC. DC pumps use 50–70% less electricity for the same flow rate. A 2,000 GPH DC pump may use only 40–60W vs 150–200W for an equivalent AC pump.