Free saltwater mix calculator. Enter water volume + target salinity, get the exact ounces of salt mix to add. Avoid the bag-then-test waste cycle.
Most reef salt mixes are formulated to produce 1.025 SG (35 ppt salinity) at roughly 0.5 cups (4 oz) per gallon of RODI water. The exact ratio varies slightly by brand. Always mix in RODI (not tap) water at room temperature, aerate with a powerhead for 12-24 hours before testing or use, and verify final salinity with a calibrated refractometer.
Common mistake: dumping salt into a tank with livestock to "raise salinity." Always mix salt in a separate container with full aeration; never add dry salt directly to a display tank.
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