💧 Return Pump Size Calculator
Find the right return pump GPH for your sump setup based on head height and plumbing.
Vertical distance from pump to tank return
Results
Required Pump Rating
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Look for this GPH rating at 0' head on pump curve
Desired Flow
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Effective Head
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Head/Friction Loss
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Desired GPH = Tank gallons × Turnover rate
Effective head = Physical height + (elbows × 1 ft each)
Required pump = Desired GPH × (1 + head × 10%) × pipe friction
Effective head = Physical height + (elbows × 1 ft each)
Required pump = Desired GPH × (1 + head × 10%) × pipe friction
Sizing Your Return Pump
The return pump is the heart of a sump-based aquarium system. Undersizing causes poor flow and dead spots; oversizing wastes electricity and creates excessive noise.
Turnover Guidelines
| System Type | Turnover Rate |
|---|---|
| FOWLR / Freshwater | 3–5× |
| Mixed Reef | 5–7× |
| SPS Dominant | 7–10× |
Head Pressure Explained
Head pressure is the vertical distance from the pump to where water returns to the tank. Every foot of head height reduces flow by approximately 10%. Each 90° elbow adds roughly 1 foot of equivalent head pressure. Use the largest pipe diameter practical to minimize friction losses.