DIY Chiller
I have 4 compact fluorescents - 2 actinic and 2 95,000k on a 90 gallon reef tank. The temperature of my aquarium was reaching 89F. The temperature was so high because we have a computerized thermostat for our home and the temperature in the house is allowed to go to 80F when we are gone for the day.
I placed a small fan to blow the heat from the lamps away from the tank and the temp went o 82F. I bought a swamp cooler and placed it to blow on 2 sides of the aquarium. At first there was no change and then I turned off the small fan and the temp went to 72F. The cooler was $140 and has an air filter. We get cooler, humidified, clean air to breath and our tank temperature is in the proper range.
I don't know what it costs to run the swamp cooler but it should not be much more than a fan. I have to add water about once per week. It makes a fan noise but it is not as loud as other fans.