cichlid tank temp/ color change

Question
I have a 3" Acai male cichlid on his own in a 30 gal tank. He's not very
friendly to any other female I add to the tank, even if I reorganize the multiple
plants, caves and other hiding spots. With the warm weather I've been
monitoring the tank temp like a hawk and so far it has stayed in the comfort
zone of 78-80. However, last night I checked it out and found the temp was
84! My poor lil fish was hiding in his favorite cave and I had to move it to see
how he was doing in the sauna of the tank. Normally he's extremely light
silver with very faint lines and medium yellow fins, but with the water temp
increase he was almost  medium-dark blue with neon yellow fins. I obviously
took alarm to this and changed 20% of the tank's water to hopefully cool it
down. It took an hour for the overall tank temp to drop back down to 79
degrees, and the fish returned to normal coloring. What can I do to combat
the jump in tank temps during the summer without spending an arm and a
leg on a tank cooler? I live in Western New York and honestly, it's only this
hot for one or two months a year. Was the fish's color change a direct
response to the temp increase, decrease in oxygen or something else?  

Answer
Hi Christina,
  The biggest problem with warmer water in that range, i.e., around 84, is not the heat, but the decrease in oxygen.  If you make sure that you have a good airstone working all the time (in addition to any filter you might have), that higher temperature should not be a problem.   

-- Ron
  rcoleman@cichlidresearch.com
  Cichlid Research Home Page <http://cichlidresearch.com>