Ista Hydrometer

Description

The Ista Hydrometer is a simple piece of equipment used to quickly and accurately measure the salinity of the water in the marine aquarium.
Ista – Swing Arm Hydrometer

The device is very simple in both its design and use. The Hobbyist dips the entire unit into their aquarium, filling it to the top with saltwater. The unit, now full, is then removed from the tank and set on a level surface. The swing-arm within the hydrometer will rise to indicate the specific gravity (also known as relative density) of the water sample. The more dense the water, the higher the arm will rise.
The have clear indication of where the level should be and if your tank is in the higher or lower end. Please note bubbles can easily get stuck to the swinging arm of the device and cause an inaccurate reading.

Using the Ista Swing-Arm Hydrometer for Marine Tanks

This swing-arm hydrometer is a quick, affordable way to check the salinity, or specific gravity, of a marine or brackish aquarium. You dip the unit to fill it with tank water, set it level, and read where the arm settles: the denser the saltwater, the higher the arm swings. We point new reefkeepers towards it as an easy first salinity tool before they invest in a refractometer.

Stable salinity is one of the most important parameters for corals and marine fish, and in Singapore our warm room temperatures mean evaporation is brisk, so salinity creeps up between top-ups faster than many expect. Checking regularly with a hydrometer helps you catch that drift early. Tap the arm to dislodge any trapped air bubbles before reading, since a single bubble throws the result off noticeably.

Rinse it in fresh water after each use so salt creep does not stick the arm. Browse the full marine equipment range, and read our hydrometer vs refractometer comparison and salinity refractometer guide.