Reef Aquarium Calculators

Quick, accurate tools for everyday reef-keeping math. No sign-ups, no ads — just results.

Hydrometer Correction Calculator

Correct your Tropic Marin Precision Hydrometer specific gravity readings for temperature. Get your true salinity instantly.

Estimate your reef aquarium electricity costs. Itemize equipment wattage and run time to see monthly and annual energy expenses.

Calculate the right amount of activated carbon for your reef aquarium media reactor based on tank size and carbon type.

Calculate how much salt mix to add based on your water volume, current and desired salinity, and salt mix brand.

Calculate your aquarium's water volume based on tank shape and dimensions.

Calculate exactly how much magnesium supplement to dose based on your tank volume, current and target levels.

Calculate exactly how much calcium supplement to dose based on your tank volume, current and target levels.

Calculate exactly how much alkalinity supplement to dose based on your tank volume, current and target levels.

Calculate the right amount of GFO phosphate removal media for your tank volume and product type.

Calculate how much sand you need based on your tank dimensions, desired depth, and sand type.