Aquarium Systems HydrometerThis is an easy to use scientific instrument that measures both the specific gravity and salinity of tropical saltwater aqu..
The re-designed deep six hydrometer with improved calibration and bubble diffuser ensures more accurate readings of your aquarium salt levels. Also in..
Compact design with large, easy-to-read markingsIdeal salinity range clearly identified in green for added convenienceCan be permanently installed ins..