DIY Aquarium Cooling Fans

Aquarium lights can cause unwanted temperature increases in your fish tank. Instead of purchasing a premade cooling system, you can build a DIY aquarium cooling fans system that will increase the circulation of air around your aquarium lights to reduce their effect on the tank's water temperature. Since the fans only use room temperature air for cooling, you do not run any risk of over-cooling the water to below room temperature.

  1. Choosing Your Fans

    • You have three options for which fans to use in your DIY fan cooling system: you can purchase AC fans, purchase DC fans or construct your own fans. AC fans are the easiest fans to use because they can be plugged directly into any home outlet. DC fans must first run through a DC to AC adapter before you can plug them into an outlet. The advantage of DC fans are that they generally, but not always, move more air than AC fans of an equivalent size. Their small size allows easier positioning in around your aquarium. They also cost less for the amount of air moved, even after factoring in the cost of a converter. AC fans are available at a variety of stores, including most home superstores. You can find DC fans at electronics stores.

      If you have trouble finding AC or DC fans that will fit well in your aquarium setup, you can construct your own fan. Purchase a small, fast motor from an electronics store, along with fan blades of your desired size. Attach the blades to the motor, and use electrical wiring to connect the motor with a power supply.

    Positioning the Fans

    • The most common way to position cooling fans for an aquarium is to place them on one end of the aquarium, blowing air towards the aquarium. This will replace the hot air surrounding the aquarium lighting with the cooler, room temperature air. Some aquarium owners are concerned that blowing air on the lamps will damage them or effect their light output. While extremely fast moving air could do this, the fans you are using are not powerful enough to have a detrimental effect.

      You can angle the fans slightly downward so that they will also hit the aquarium water itself. Instead of just removing the hot air from around the lights, this will also cool the water itself by increasing the rate of evaporation. If you chose to do this, make sure to monitor the saline levels in your water, and be careful that the fans do not disturb your fish.

      A final method of positioning the fans is to aim them away from the aquarium, pulling the hot air out instead of pushing cold air in. This method works best if you install the fans directly in the hood of your aquarium, so that a high level of suction can occur.