Fluval Sea Hydrometer provides an accurate and convenient method of measuring specific gravity and salt level in marine aquariums.

Compact and easy to use, the hydrometer can be permanently installed inside the tank for continuous readings. Its slim, low-profile design camouflages well inside the tank and will not diminish the aesthetics of the aquarium.

It can also be used as a portable device, allowing you to take samples simply by submerging it in the water. It features large, easy-to-read markings with ideal salinity range clearly marked in green for clarity.

Salinity Refractometer by D-D The Aquarium Solution.

A Refractometer is a simple and robust way of accurately measuring the salinity within your aquarium and should be used by every serious marine aquarist.

For accurate readings every time, ideal for use in water temps from 20-29’C (68-85’F).