GlenCalc

Aquarium dosing calculator

Read the dose on the label, for example “5 mL per 10 gallons”. Use the actual water volume (less rock and substrate). Follow the label for live-animal products.

Your answer

Dose for your tank27.5 mL
Water to change13.8 gal
Dose for the new water only6.88 mL

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How we worked it out

Updated as you change the numbers.

  1. Dose = label dose × your gallons ÷ label gallons.

Method and assumptions

Water conditioners are dosed for the new water added during a change; medications and fertilizers for the whole volume. Never exceed the maker’s maximum.

Questions

How much conditioner for a 55 gallon tank at 5 mL per 10 gallons?

27.5 mL; for a 25% water change, 6.9 mL.

Sources

Method and figures checked on . Every worked answer on this page is covered by an automated test. Found a mistake? Tell us.

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