Instructions For UseRinse hydrometer with fresh water before using.Slowly fill hydrometer by dipping bottom corner fill port below water surface until water flows up and over inner weir.Dislodge air bubbles by tapping hydrometer, or pointer, gently with pencil.Placing hydrometer on a level surface, read specific gravity (inside scale) and salinity (outside scale). For most marine aquariums, recommended specific gravity is 1.020 to 1.024.Cleaning: Periodic cleaning is recommended to remove deposits that can accumulate on pointer, causing inaccurate readings. Soak hydrometer in mild acid (vinegar) for 30 minutes, then rinse.
Aquarium Systems Instant Ocean Hydrometer
Dimensions: 6"Height