The Secret To Keeping Your Aquarium Cool

There are many different reasons aquarists need to keep their aquarium cool. Just some of these reasons can be:

  • To stop high seasonal temperatures affecting species sensitive to heat
  • To enable certain species to hibernate, something they often need in order to breed
  • To enable the tank temperature to be more like nature intended, which will make the animals inside the tank happier and healthier

There are several general methods you can use in order to keep your aquarium cool. Different methods suit different people depending on their set up, so if you’re unsure which is best, read up on what you want to achieve and speak to those who have already achieved it. By seeing what others do successfully, you can then try those methods yourself in order to achieve success.

Put The Tank Somewhere Cold

This is really the first thing you should be trying before anything else as the position of your tank can drastically affect it’s temperature. If you have a shaded room or a room with a stone floor (usually always cold) then move the tank there (if practical). The tank should never be in direct sunlight, next to a radiator or in a room where an open, gas or electric heater is used regularly.

Use Air Conditioning

If you already have air conditioning in your property then you should be able to set it up so that cooler temperatures go into the room where your tank is. However, it’s most likely if you live in the UK that you do not have air conditioning set up (when do we ever need it?) in which case you might want to buy yourself a separate unit or see how feasible it is for you to have one installed. This isn’t achievable for most of us, but if it is an option for you it might be worth considering as it can be a good method of cooling.

Invest In An Aquarium Chiller

Plenty of reputable retailers sell aquarium chillers, and they can be extremely effective. The two main types of chillers are thermoelectric and refrigerated. You’ll pay more for a refrigerated chiller but it will be more effective than a thermoelectric chiller which is less costly. If you are planning on paying for a more premium chiller, make sure you speak to an advisor (most companies will happily advise you) on which type is best suited to your needs.

Get Scientific

Evaporation is a really effective way to reduce the water temperature in your tank, however, it is quite a scientific process – although you don’t necessarily need to know the science behind it to do it. The first thing you could try is using a screen top which will lower the temperature by a degree or so naturally. As well as using the screen lid you could use airstones or a spillage filter.

Put A Fan Over The Tank

By blowing a wet towel placed on the outside of the tank with a fan, you can reduce the temperature inside the tank.

Frozen Bottles Of Water

Freeze a bottle of water and place it in the tank (don’t forget to remove some water before doing this), and fill another one up whilst that one is in the tank so you can switch them around when the one in the tank has melted. Ensure you replace the water in the bottles with filtered, dechlorinated water regularly in case they leak.


Make clean, filtered, dechlorinated water ice cubes and place them in the tank (don’t forget to take some water out first or you’ll have a flood!). This should be done in the evenings to replicate the cooler night times the animals would experience in the wild.

So as you can see, there is no specific ‘right way’ to cool your tank, but there are plenty of options for you to choose from. Generally the easiest option is to buy a device specifically designed to do the job of cooling your tank. However, it’s always worth considering lots of options and learning about different methods anyway, just in case the equipment you do buy fails and you need a quick cooling method while you replace equipment.