Cooling Summer Aquariums


Q: HB wrote,

Nippyfish, my aquarium is getting too warm for my fish now that summer is here. I don’t have A/C and I’m afraid my betta is going to cook. The temperature is already up to 82F. What can I do?

A: As summer approaches many of us will have to struggle with warmer water temperatures. Very warm temperatures can be stressful to fish just as very cold temperatures are and can lead to common illnesses. Flavobacterium columnare, for example, often rears it’s ugly-fungal-looking head in the summer after a quick warm up of the tank water. Fortunately for those of us who keep bettas and other tropical fish the tolerable temperature zone is a little higher and easier to manage then it is for our cool water counterparts.

At 82˚F, your aquarium has only just reached the upper threshold of what Betta splendens prefer. At this point you really don’t have anything to worry about. Should the temperature continue to rise you may want to consider some simple steps to beat the heat.

First, it seems obvious but make sure your fish tank is out of direct sunlight. Sure bettas look pretty on the window sill but I promise they won’t look nearly as impressive if they’re belly up.

Secondly, larger water volumes take a lot longer to heat up then a small tank so if you expect a hot summer, or worse, hot days and cool nights you will certainly benefit from getting your betta bigger digs. A 5 gallon tank will show smaller temperature fluctuation from day to night then a 1 gal and is still quite compact. An even better arrangement is a 10 gallon, which can keep temperatures quite stable for a long time. Cheap or even free 10 gallons aquariums are everywhere. My favorite place to pick up a quick 10 gal set up is on Craigslist.org.

Thirdly, trade in that plastic lid and light hood for a screen or mesh top. You can buy them for standard size tanks but if you at all resemble the typical penny-pinching aquarist you can make one out of window screening and cardboard. When you’re done you can take the money you saved and buy more bettas.

Lastly, set up a small house fan so that it blows over the surface of your aquarium. Believe it or not, this simple action works wonders for cooling the water. Just remember that evaporation will occur much quicker then usual so you will need to replace lost water daily and most importantly, don’t forget that electric fans and water don’t mix. Give yourself ample room and watch those cords so no one gets zapped.

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Christie F is a Betta splendens hobbyist that enjoys spending time caring for her fish and helping new betta keepers learn the ropes. More posts by:

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