Filter Flow Rate Calculator
Check whether your filter turns over the tank enough times per hour.
How it works
Turnover (×/hr) = Filter flow rate (L/h) ÷ Tank water volume (L). Aim for 4× for low-stock/planted tanks, 6-10× for community tanks, and 10×+ for messy or heavily stocked tanks. Account for media reducing rated flow by ~30%.
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Formula & Method
Turnover (×/hr) = Filter flow rate (L/h) ÷ Tank water volume (L). Aim for 4× for low-stock/planted tanks, 6-10× for community tanks, and 10×+ for messy or heavily stocked tanks. Account for media reducing rated flow by ~30%.
Example Calculation
A 200 L tank with a 1000 L/h canister = 1000 ÷ 200 = 5× turnover. After media losses (~700 L/h effective) it's ~3.5×, so you may want a larger filter.
Frequently Asked Questions
What turnover rate do I need?
6× per hour suits most community tanks. Reduce flow for bettas and increase it for cichlids and goldfish.
Does media reduce flow?
Yes. Rated flow is for an empty filter; expect 20-40% less once filled with media and over time as it clogs.