Reef tank calculators

CALCULATOR · VOLUME

Aquarium volume calculator

Convert tank length × width × height (inches or cm) to gallons and liters, with a table of real reef tanks and their true water volume after rock and sand.

CALCULATOR · HEATING

Aquarium heater wattage calculator

What size heater for your reef tank? 3–5 watts per gallon of actual water volume, split across two elements on a controller. Full table from 10 to 300 gallons.

CALCULATOR · SALT

Reef salt mix calculator

How much salt for a water change? Cups, grams and cost for a target of ~35 ppt, priced across five mainstream reef salts with real 2026 per-gallon costs.

CALCULATOR · DOSING

Reef 2-part dosing calculator (Alk / Ca / Mg)

Daily 2-part alkalinity dose in mL from your measured dKH/day consumption and water volume, for ESV B-Ionic and BRS/DIY soda ash. Dosing starts past ~0.45 dKH/day.

CALCULATOR · FLOW

Reef tank flow & wavemaker calculator

Total in-tank flow (GPH) and number of wavemakers by coral type and tank size — softies 10–20×, LPS 20–40×, SPS 40–60×, mixed 25–40× turnover.

CALCULATOR · CUC

Reef cleanup crew calculator

A starting reef cleanup crew by tank size: grazing snails, Nassarius snails and hermit crabs. Starting counts to tune to your algae, not survival promises.

CALCULATOR · COST

Reef tank build cost calculator

Budget, mid and premium equipment cost ranges for a reef build by size, tank type (AIO or sump) and coral type — from real 2026 catalog reference prices. Equipment only.

CALCULATOR · SALINITY

Salinity converter: SG ↔ ppt ↔ conductivity

Convert reef salinity between specific gravity, ppt and conductivity at 25°C. Reef target: 35 ppt ≈ 1.0264 SG ≈ 53.0 mS/cm. Full reference table 28–38 ppt.