Aquarium product dose calculator
Scale a product’s label dose (e.g. 5 mL per 10 gallons) to your tank or water-change volume, in gallons or liters.
How it works
Most water conditioners and additives give a dose per volume, e.g. “5 mL per 10 gallons”. Your dose = label amount × (your volume ÷ label volume), after converting both volumes to the same unit. For a water change, enter only the volume of new water if the label says to dose the new water.
Example: 5 mL per 10 US gal, treating 25 US gal: 5 × 25 ÷ 10 = 12.5 mL. Treating 50 L with the same product: 50 L = 13.21 US gal, so 6.6 mL.
This tool only does arithmetic. Always follow the product label. It does not give advice on treating sick fish; for that, talk to an aquatic veterinarian.
Sources
Related tools: Tank volume by shape · Gallons ↔ liters & water weight · Water change & nitrate dilution · Substrate / gravel amount · Heater size & warm-up time