HI Marineist4life, welcome to the site! I have very temp sensitive fish in a 110g tank here in Texas and have found the little 6-inch clip-on desk fans work well. You can find them at Target, Walmart, etc. and when clipped to the edge of the tank they need to be blowing straight down (perpendicular) on the water only about 3 to 4 inches over it. If they are installed at an angle - like trying to blow the heat out - that will not be affective. For me each fan is worth 2-degrees reduction.