Tank got up to 81 degrees

Any Idea how well this actually works? I was considering it for an emergency "my ac failed OMG" type of backup plan for summer.

 

Evaporative cooling works very well. Many people do this instead of buying chillers. However, if your air conditioning goes out, this will lose effectiveness as the ambient room temperature increases.

 

During summer my tank temp is always fluctuating it gets as high as 84 in the day and 75 at night. Definitely not a consistent temperature in my tank, but it seems to have no effect on any of the inhabitants.

 

I can join the general theme here with higher temps not being disaster. I've had my tank hit 85 and nothing took a turn for the worst because of it. I run @ 82 on average, but I recently reinstalled my fans which brought the temp down a couple degrees.

Like Inwall said, the scale of the heater is not to be trusted, I've found the very same in my experience. It's normally like 2 degrees off, higher or lower.