It’s designed to go outside the aquarium and below the waterline. Better accuracy than floating thermometers; Cons. Floating thermometer is a great choice for all the aquarium hobbyists and it provides you an actual result of your aquarium temperature. Lomodo 4 Pack Floating Thermometer Aquarium Glass. You attach it horizontally by using the adhesive. What We Like About UPLY Digital Aquarium Thermometer. Buy Now from Amazon. The thermometer … ... Best Seller in Aquarium Thermometers. All in all, if you are looking for an inexpensive thermometer for your betta tank that is an alternative to a floating aquarium thermometer, the SunGrow Digital Betta Thermometer … This type of thermometer is very cheap and most of these thermometers are made of glass which makes them considerably more fragile than the other types of thermometers. Reports of residue on the unit; Reports of broken units; Reports of inaccurate readings; Summary. If you’re not a fan of suction cups, you’ll be glad to know that this thermometer can function just as well by floating … This thermometer measures 0.75" x 4.25" and weighs a puny 0.3 ounces. Operating the device is simple too. Hofun Swimming Pool Thermometer, Cute Design,Swimming Pool Water Thermometer with String, Outdoor Floating Thermometer for Swimming Pool, Bath Water, Spas, Hot Tubs, Aquariums and Fish Ponds. Marina Floating Thermometer … 4.3 out of 5 stars 178. The large digital display on the UPLY Digital Aquarium Thermometer is easy to read due to the large numbers. The back of the thermometer senses the temperature inside the aquarium …