Free calculators and tools for saltwater reef hobbyists. No account required.
Calculate your tank's water volume for rectangular, bow front, cylinder, hexagonal, L-shape, and corner pentagon shapes. Accounts for rock, sand, and equipment displacement.
Check if your water parameters are in the ideal range for reef, FOWLR, or freshwater tanks. Get actionable recommendations when levels are off.
Calculate exact dosing amounts for calcium, alkalinity, and magnesium supplements. Supports BRS, ESV, Brightwell, and generic products.
Calculate how much salt mix you need for water changes. Supports Red Sea, Instant Ocean, Fritz, Tropic Marin, and more.
Check compatibility between 36 common reef fish species. See aggression level, reef-safe status, tank-size minimums, and pair-specific warnings.
Estimate safe aquarium stocking based on tank volume, filtration, and 36 common saltwater fish species. Includes compatibility and minimum tank warnings.
These tools give you a snapshot. My Reef Log gives you the full picture - log water tests, track trends, manage livestock, and stay on top of maintenance.
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