Parameter guides

Reef aquarium Salinity guide

Many reef systems are maintained near natural seawater, around 35 ppt or 1.026 SG at 25°C. Track repeated readings and recent care instead of treating one number as a diagnosis.

When the reading is higher

Confirm calibration and temperature compensation, then review evaporation and top-off behavior.

When the reading is lower

Confirm calibration, recent water changes, top-off volume, and salt-mixing procedure.

Units and review

ppt / specific gravity · Content reviewed 2026-09-02. Verify urgent livestock, dosing, and treatment decisions with qualified sources and product labels.