Calculator Index
All aquarium calculators
Every aquarium calculator on ReefCalcs grouped by what kind of problem it solves. Chemistry tools default to US gallons and dKH; toggle units inside each calculator. Most work for freshwater fish tanks too — substrate, volume, heater wattage, and weight are unit-agnostic about whether the water is salty.
Water chemistry
BRS calculator alt
Open alternative to BRS’s reef calculator. Same Randy + BRS Pharma recipes, plus AFR, Red Sea, Triton.
All-For-Reef (AFR)
Tropic Marin AFR daily dose by tank volume and dKH consumption — 1 mL per 25 L per dKH.
Red Sea Foundation
Red Sea Foundation A/B/C daily doses with the manufacturer’s per-mL ppm constants.
Alkalinity dosing
Randy Recipes, BRS Soda Ash, Tropic Marin AFR, Red Sea Foundation B, Triton Base 1.
Calcium dosing
Randy CaCl₂, BRS Pharma, Red Sea Foundation A, Triton dry.
Magnesium dosing
Randy Recipe 3A, BRS Pharma, Red Sea Foundation C, Triton dry, Tropic Marin Bio-Mg.
Kalkwasser
Saturation mix and daily-dose by evaporation rate.
Reef health
Eight-parameter snapshot with colour-coded bands and one-click fixes.
Water change
Predict the post-change parameter for any dilution.
Salt mix
Dry salt mass per brand — Instant Ocean, Reef Crystals, Red Sea, Tropic Marin, Fritz RPM.
Salinity
SG ↔ ppt ↔ mS/cm with hydrometer temperature correction.
CO₂ / pH / alk
Henderson-Hasselbalch carbonate solver. Two of three; we give you the third.
Tank geometry
Aquarium volume
Rectangular, cube, cylinder, hex, bow-front. Inches or cm in; gallons and litres out.
Aquarium weight
Total filled weight plus PSI on the floor. Plan the upstairs build.
Substrate
Pounds of sand or crushed coral by published CaribSea bulk densities.
Aquarium gravel
Pounds of gravel for any freshwater fish tank — 1–2 in bed, exact bag count.
Aquarium sand
Aragonite or silica sand by footprint and depth. SSB / DSB / bare-bottom guidance.
Glass thickness
Minimum annealed or tempered thickness with SF=3.8. For DIY builds and sanity-checking imports.