The JBJ C-Breeze is a small cooling fan for tanks up to 40 gallons. It includes a mounting bracket for attaching the fan to a tank with a 1/2" rim or less. The C Breeze is very affordable and a great option for cooling smaller tanks. The design keeps the fan behind the tank and out of view with a small deflator pointing the airflow over the water’s surface. We use one of these fans on our 30-gallon office tank, and it reduces the temperature by about three degrees.

The Tunze AquaWind Eco Chic is a larger fan that can cool a 200-gallon aquarium 3-7 degrees, depending on the room temperature. It is not as discrete as the JBJ fan, but it is much more powerful and is a better choice for larger tanks. The AquaWind has a bracket that will work on tanks with 3/4" glass, and it also can pivot so the airflow is directed at the water’s surface. The AquaWind is a pretty expensive fan, but it is much more affordable than a chiller.

The Octo Variable Speed Fan is one of our favorite aquarium products. If you have been keeping aquariums for a long time, you likely remember the Ice Cap cooling fans commonly used to keep metal halide fixtures and canopies cool. The Octo Variable Speed Fan is the same, but with a USB power supply. These fans are great for removing heat and humidity from the aquarium cabinet and canopy. While this doesn’t directly cool your aquarium, it can help by keeping the air around your sump cool and dry. The lower humidity will also help wooden aquarium furniture and electronic gear (such as power supplies and controllers) last longer, as the fan creates a cooler, drier environment. The fans are variable-speed and include a temperature probe that automatically speeds up and slows down throughout the day based on temperature. This keeps the fans very quiet until things get very hot.