How do you keep goldfish cool in the summer?
 

We have a 5.5 gallon tank with two twin-tailed goldfish in it. (After we bought the goldfish we found out how big they can get and that they are going to need a much larger home very soon - oops.) We live in California and have no air conditioning, and as the weather is warming up, so is the tank water! Normally goldfish enjoy an environment around 68 degrees, so I am told, and today the temperature spiked to 80. The poor things must be suffering, but I don't know what to do to keep them cool. I have heard of chillers, but this odd-shaped, small little plastic tank cannot accommodate one, and I am also told that a chiller is quite costly.

Thanks for any advice!

use ice cubes or keep your house cool without turning on the aquarium heater. i too live in cali, in the northern region and let me tell you the valley is a difficult place to keep a tank up and running at a normal temperature without having to cough up some serious dough. but investing in a cooler is not a bad idea, maybe even a life saver(literaly), but i stick with the cubes and the air conditioner.

I've used Polar-Pacs placed in ziploc bags too.
Sealed up they keep some air surrounding the Polar-Pac so it floats.

Thanks for the advice! Yes, I have an extra air stone in there in addition to the filter/aerator. They just seemed happier with the extra oxygen. I will freeze the coke bottle today.

Here's to happier goldfish! :D