Measure your salinity and specific gravity with a hydrometer
Maintaining stable water conditions in a saltwater aquarium is important to the health and well-being of your tank inhabitants. Salinity is one of the key water parameters you’ll need to keep an eye on.
The least expensive way to measure the concentration of salt in a marine aquarium is by using a hydrometer. We carry two basic types of hydrometer for saltwater aquarium use: plastic boxes and glass models.
If you’re wondering how to use a hydrometer, it’s actually very simple. A glass hydrometer floats but will to sink to a certain level based on the density of your water. This is when to read the measuring line. You can perform this test outside the aquarium in a cup of water to avoid breaking glass in your tank. To use a box hydrometer, fill it with water and a swing arm will rise to a certain point to provide your salinity reading in in parts per thousand (ppt) and specific gravity (sg). Be sure to clean the unit afterward to prevent dried salt from throwing off your measurements.
If you have questions about hydrometers, please contact our experts
for free support or sales advice. You might also considering checking out our Reef Tank Parameters Chart
and reading How to Measure Salinity in a Saltwater Aquarium
to learn more about measuring salinity.
The re-designed deep six hydrometer with improved calibration and bubble diffuser ensures more accurate readings of your aquarium salt levels. Also includes a built in base so you can rest the hydrometer on a counter top or other ...
Instant Ocean Hydrometer`s new improved design delivers precise full-range salinity and specific gravity readings - accurate to 0.001 - every time. Easy-fill convenience keeps hands dry when filling. It has a durable, permanent ne...
Hagen Living Sea Hydrometer with Thermometer—Small
Easy to read
Thermometer—C & F
Fluval Sea Hydrometer provides an accurate and convenient method of measuring specific gravity and salt level in marine aquariums. Regular testing is strongly recommended as stable salinity levels are essential for the health of m...