Ensure that your equipment is reading correctly and your aquarium is at the right salinity with Tropic Marin's High Precision Hydrometer. 

Many tank inhabitants are sensitive even to minor changes of the water conditions. Unfortunately as we've all experienced, salinity reading equipment as well as calibration solutions can drift over time and it can occasionally be a challenge to ensure equipment is always calibrated correctly. That's where the Tropic Marin Hydrometer comes in. The Tropic Marin High Precision Hydrometer provides an exact and reliable measurement of specific gravity, and it never needs to be re-calibrated, so it's a perfect reference device for calibrating other equipment.

• High precision hydrometer for determining the specific gravity in aquariums
• Designed to float vertically
• Handmade
• Maximum deviation: 0.001 at 77° F (25° C / 77° F)
• Scale from 1.021 to 1.031
• Resolution: 0.0001
• Recommended range: 1.025 to 1.027 (at 25° C / 77° F)

Note: The specific gravity is temperature dependent. With increasing temperature the specific gravity decreases. Therefore, the measured water temperature should be 25 °C / 77 °F to obtain a correct result. For an exact, reliable measure of the specific gravity, we recommend to use the Tropic Marin® High Precision Hydrometer.

• Fill the measuring cylinder with maximum 400 ml saltwater (water temperature = 25 ° C / 77 °F).

• The hydrometer should be dry and clean.

• Gently place the hydrometer into the water until it floats freely.

• Now read the specific gravity on the blue part of the scale of the hydrometer at the level of the water surface - NOT at the level of the meniscus, which is creeping higher at the edges!

• To avoid any distortion of future measurements, rinse the measuring cylinder well with fresh tap or reverse osmosis water to remove salt residues after each use.