Return Pump Flow Rate Calculator
Work out the return flow your reef needs, then see which pumps still hit that flow after head height and pipe losses — with a clear “why this works” for each pick.
1. System volume
Display + sump − rock/sand is ideal. Display-only is fine for a starting point.
2. Tank type
Sets turnover targets through the return (not wavemaker flow).
3. Plumbing size
25mm — solid default for most mid–large reef returns.
4. Head height & fittings
Sump waterline up to return outlet. Required for accurate picks.
Result
Estimated volume—
Target turnover—
Flow needed at outlet—
Sweet spot—
Plumbing—
Effective head*—
Recommended pumps
Picked by estimated flow at your head (not open-flow sticker numbers). In-stock first. DC pumps can dial down to the sweet spot.