Sera Marin Hydrometer 5/8" dia x 6-1/2"

Floating glass hydrometer for measuring aquarium specific gravity Extremely simple-to-use hydrometer for fast and effortless testing Monitor and maintain proper specific gravity in saltwater aquariums Extreme ease of use makes the standard floating hydrometer a classic favorite. Measuring aquarium specific gravity is as simple as floating the Sera Marin Hydrometer in your marine aquarium. Features measurement range of 1.000-1.040 with graduation increments of 0.01. The Sera Marin Hydrometer is calibrated at 77 degrees Fahrenheit (25 degrees Celsius) and measures 5/8" diameter x 6-1/2".Please click on "More Information" for tips on testing.