Information about Thermometers & Hydrometers

Aquarium Thermometers

Thermometers are used to monitor the correct aquarium water temperature. This is of great importance for maintaining the correct environment for your aquarium fish. Different types of fish prefer different water temperatures.

Thermometers are one of the least expensive items of aquarium equipment. Since most fish are extremely temperature sensitive, knowing your tank temperature is very important. See below for a table of some of the common kinds of fish and their approximate water temperatures.

Type	Approx. Temp Range
Gold Fish	20° - 23°C
Betta (siamese fighting fish)	24° - 29°C
Tropical Fish	22° - 26°C
Marine Fish	22° - 26°C
Reef Tank	26° - 28°C

There are different types of thermometers:

• Floating Thermometers - these can be attached to the inside of the aquarium with a suction cup.
• Stick on Digital Thermometers
• Stainless Steel Thermometers
• Digital Sensor Thermometers

Aquarium Hydrometers

Hydrometers measure specific gravity and salinity in saltwater, marine and reef aquariums. Salinity is a measure of the concentration of dissolved salts in the tank water. More about Hydrometers...