Hydrometer & Thermometer

Fluval Sea Hydrometer provides accurate measurements of specific gravity and salinity in marine aquariums. This easy-to-read hydrometer has clear markings and is compact and easy to use and can be installed inside a tank permanently for continuous...

Instant Ocean Hydrometer is accurate, reliable water test equipment is absolutely vital to creating and sustaining a healthy, successful marine environment.Accurate to 0-001Durable, Permanent Needle MountEasy-Read, 2-Color Scale with Safe ZoneExtra-Wide...