Aquarium tool
Water change and dosing calculator
Plan a water change and scale a treatment dose to your tank.
How the nitrate sum works
Replacing part of the water cuts nitrate by that share, but your tap water brings some back. The calculator uses the nitrate in your tap water, so it can tell you when water changes alone cannot reach your target.
Doses
Copy the dose from the product label. Products differ, so we do not store doses. Always follow the label for timing, and never exceed it.
More tools
Tank compatibility checker
Plan your stock before adding it to your aquarium.
Aquarium volume calculator
Work out how much water your tank really holds, and what it will weigh when full.
Fish finder
Find the species that suit your tank size and water.
Heater and filter calculator
Size a heater and a filter for your tank.
Cycling helper
Find out where your tank is in the nitrogen cycle.