Last year I did not run a chiller at all and had no problems. But this year seems to be a different story. My temperatures are way above what is reasonable and I really need to get a chiller on the tank. Anybody have ideas for a diy that actually works? How about cheap commercial ones that are out there? My display is 75 gallons and I have about a total of 110 gallons of water, how big should I go for the chiller?