The Instant Ocean Aquarium Hydrometer is a simple, reliable way to measure the specific gravity and salinity of your saltwater aquarium. Just fill it with tank water and read the easy swing-arm indicator, no calibration or guesswork needed. An essential tool for mixing salt and keeping your saltwater tank stable.Features Measures specific gravity and salinity at a glance Easy-to-read swing-arm indicator No calibration required Durable and simple to use A must-have for mixing salt water How to Use Fill the chamber with aquarium or freshly mixed salt water Tap out any air bubbles clinging to the swing arm Read the salinity and specific gravity where the arm settles Rinse in fresh water after each use Specifications Brand Instant Ocean Type Swing-arm hydrometer Measures Specific gravity and salinity Best for Saltwater and reef aquariums Pair It With For higher precision, step up to a salinity refractometer Mix water with salt mixes Browse more testing gear Frequently Asked QuestionsWhat does it measure?The specific gravity and salinity of your saltwater, so you can keep it in the right range for fish and corals.What salinity should I target?Most reef tanks target a specific gravity around 1.025. Fish-only tanks can run a little lower.Do I need to calibrate it?No. Just rinse it after use and tap off any air bubbles for an accurate reading.
