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Thermometers & Hydrometers for Aquariums

One of the most important aspects of caring for your pet fish is to make sure the water temperature in their tank is at the correct temperature. If you care for saltwater fish, in addition to making sure the temperature is correct, you also have to make sure the water has the proper salinity (salt) level. To regularly and accurately check your tank’s water and salinity levels, you will need a good quality, reliable aquarium thermometer and hydrometer, which are both available on the Zen Pet Supplies’ online store. Our aquatic thermometers and hydrometers are easy to read and reliable. You’ll love our large selection of digital thermometers and hydrometers, and we even carry a combination hydrometerthermometer that floats in your tank. Whether you’re looking for a standing, suction or floating thermometer, you’ll find it here, and if you want to buy a separate hydrometer, you’ll find those here, too. Be sure to check back soon if you can’t find what you need as we update our inventory regularly.

Hydrometers in their truest sense measure the “specific gravity” of water, which means these tools let you know how much of a substance is in the water compared to the amount of water itself. But more simply put, hydrometers lets aquarists (another fancy word!) know how much salt is in the water they’re testing. Knowledgeable saltwater fish owners will know exactly what the hydrometer should read to provide optimal salinity levels for your fish. Experienced fish owners will tell beginners that testing water frequently is one of the most important aspects of providing a safe and healthy habitat for your fish. When it comes to the different types of hydrometers on the market, you’ll find a standard floating hydrometer, which consists of a glass "float" that goes into the tank, and how high it floats indicates the specific gravity. Another type is the swing arm hydrometer that has a plastic float attached at a pivot point, and that float swings up to a certain position depending on the specific gravity of the water.

Our reliable, safe and easy to read thermometers will give an accurate reading every time. Even the most inexpensive thermometers will give reliable readings, so you’ll be able to consistently monitor and modify the water in fish tanks of any size. We have thermometers that work in both saltwater and freshwater aquariums, and you can choose between stick-on, floating and standing thermometers. You’ll be amazed to see how inexpensive even the highest quality fish thermometers and hydrometers are at Zen Pet Supplies.