Free aquarium tools

Small calculators and trackers for everyday fishkeeping. They work in your browser, with no account and no sign-up.

• Nitrogen cycle tracker

  Log ammonia, nitrite and nitrate tests and see when a new tank is ready for fish.

  Open tool →

• Aquarium volume calculator

  Litres, US and UK gallons for rectangle, cylinder, bow-front and hexagon tanks, plus water weight.

  Open tool →

• Water parameter checker

  Compare your test results with the usual ranges for freshwater, planted, saltwater, reef and brackish tanks.

  Open tool →