How Can I Keep a Tank Cool During the Summer?

[Dr. Fish]

I recently got a 9 gallon tank for my office. It is so peaceful to have it there during the work day. The issues is, I have a west facing window on the top floor so my office bakes in the sun all afternoon/evening. During weekdays, the AC is on and I have a fan going with the office door open. However, on weekends, the AC is turned off (not my choice) and the door has to stay shut. So, the office is like an oven. After an unseasonable warm weekend a few weeks ago, I came in to find my water temp at 84+ degrees. I'm very worried about how hot the water will get on summer weekends even if I do come in for a few hours on Saturday afternoons to do water changes and can open the door and let the office cool down a bit. Any ideas of how to keep the water cool? I have have a betta and a few other fish so ideally the temp is somewhere between 74 and 80 degrees. Thanks!

[Mmiller2001]

The truth is, the tank is never going to be cooled lower than the ambient temperature of the room. Add filter and pump heat to that equation as well. However, fans blowing over the top of the tank will help cool things down but again, ambient temperature maters and evaporation will increase.

The next option is expensive, but works. You can run a chiller on a controller to keep the water cool.

Hope this helps.

Edited May 10, 2021 by Mmiller2001

[Emika_B]

Dr. Fish - I live in Hawaii and my house isn’t temperature controlled (no AC or heater), so my tank gets over 79 degrees pretty much every day.  I use an InkBird controller for a heater and a set of fans.  When the water gets to 79 the fans kick in.  WIth the fans the tank generally hasn’t gone over 82.  It can take all day and into the night to get back down to 77.

It does mean the tank can’t have a solid lid; I use egg crate light fixture cover.  Evaporation can be an issue so be prepared to top off more frequently.  I’m not sure how effective the fans would be if there was no ‘fresh’ air but I have a feeling having air moving is better than nothing.  Oh, and someone mentioned adding more surface agitation, so add an air stone.

[Michaelmcg]

Maybe you could cool the room with a swamp cooler to lower the ambient temperature. If you make it big enough you should be able to make it last a weekend.

[Ken]

One of those little USB fans blowing across the top of the water? Get a little evaporative cooling going.