Want to beat the heat without beating up your wallet? Skip the expensive chillers and go straight to the inexpensive electric fans. By adding a small fan over your aquarium or sump, your aquarium’s temperature can drop significantly. This is due to evaporative cooling, which as its name suggest comes from increased evaporation of the aquarium’s water. As the water evaporates, it cools the air around it, bringing down the overall temperature of the aquarium. If you don’t want to go this route and increase evaporation, you can use a fan to blow cool air over the light fixture. This will help the hot air escape and even improve the life of the bulbs.