During the hot weather seasons when heat waves hit, you may struggle to keep your aquarium water cold enough for goldfish, goodeid livebearers, axolotls, and other cool water species. While it is relatively affordable to warm up the water with a heater, it can be much more expensive to buy equipment that reliably cools down the temperature. One simple tool to start with would be some kind of digital thermometer with an alarm that beeps if the water gets too hot (or cold). Then you know when it’s time to try one or several of these five techniques to lower the temperature and help your animals get through the summer.
1. Remove Heat Sources
The easiest method is to remove all unnecessary equipment — such as the heater, UV sterilizer, skimmer, and even hot lights. All of these devices use wattages of power and become sources of unwanted heat in the tank. In terms of lighting, consider switching to an LED light if you haven’t already because they tend to produce less warmth compared to other types of lighting. Also, a sponge filter that runs off a simple air pump may produce less heat compared to a powerful canister filter.
2. Change Locations
If your aquarium is exposed to direct sunlight throughout the day, consider moving it to a cooler, shaded area of your home. Even indirect sunlight can increase the temperature, so if your tank is in a room with lots of windows, keep the curtains closed during the daytime if at all possible. Besides sunlight, sources of hot air can also have a big effect on your fish tank, so move your aquarium away from any heating vents or exterior doors that let in hot air from outside every time they are opened. Appliances — such as an oven, dryer, or even a gaming console blowing out hot air — can also give off lots of heat.
In cases where the aquariums are in a rack or shelving system, put your cool water fish in the bottom-most tanks. Because heat rises, the difference in temperature between the top-most and bottom-most fish tanks can vary by several degrees, so we want to take every advantage possible. In fact, many people keep their axolotls in the basement where it’s cooler year-round because all of the conditioned air sinks down there while the warm air rises to upper floors.