Hydrometer

For determining the specific gravity with a hydrometer in saltwater aquaria

Product description:

The salt content in saltwater is usually measured as specific gravity (also sometimes called relative density) and is one of the most important water parameters. Many tank inhabitants are sensitive to even minor changes of the water conditions. These should therefore be kept as constant as possible in the optimum range for each tank.

The specific gravity of natural seawater of 35 ‰ (psu*) is 1.026 – compared to water measured at 25 °C / 77 °F.

Our recommendation for aquarium water at 25 °C is 1.025 - 1.027 (depending on the tank type), which can be read in the blue part of the scale on the Tropic Marin® High Precision Hydrometer.

Product features:

Tropic Marin® High-Precision Hydrometer: 

• Maximum deviation: 0.001 at 25 °C / 77 °F

• Scale from 1.021 à 1.031

• Resolution: 0.0001

• Recommended range: 1.025 to 1.027 (at 25 °C / 77 °F)

Material:

The Tropic Marin® High-Presision Hydrometer is made of mouth-blown glass. Made in EU.

Method:

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.

DO NOT CONFUSE: The “Tropic Marin® Aräometer”, which is used in German speaking countries, has a scale with a green printing and the indication ‘Dichte/density’.

We recommend different salinities for various tank types: Tabelle