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Aquarium Filter Turnover Calculator

Compare rated and estimated filter turnover using aquarium water volume, flow rate and an optional flow adjustment.

Calculation inputs

Use the actual water volume; dimensions may include space taken up by substrate and decorations.

0–100%. This is an assumption, not a measurement.

The adjustment is an assumption, not a flow measurement. Head height, tubing, filter media and buildup can reduce actual flow. No single turnover rate is automatically suitable or unsuitable for every aquarium.

Results

Enter the inputs, then select Calculate.

Your calculation inputs are not stored in a user database by Today Tool Hub.

How to save

How to use

  1. Enter actual water volume and rated filter flow in their respective units, then choose an estimated effective-performance percentage.
  2. Rated flow times the performance percentage gives estimated effective flow; dividing by water volume gives turnovers per hour.
  3. The performance percentage is your assumption. Compare the estimate with measured flow under the actual head, plumbing and media conditions.

How this calculator works: enter a number, for example 1234. Do not include unit names.

Formula and example

Estimated actual flow = rated flow × efficiency percentage ÷ 100
Turnover per hour = flow per hour ÷ aquarium water volume

A 600 L/h filter on a 45 L tank has a rated turnover of about 13.3 times per hour. At a 70% flow assumption, estimated flow is 420 L/h and turnover is about 9.3 times per hour.

Frequently asked questions

What does 100% mean?

It uses the stated flow rate without a reduction. It does not confirm that the installed filter delivers that flow.

Can I use US or Imperial gallons?

Yes. Volume and hourly flow units can be selected independently and are converted to a common basis before calculation.