Hi, I have a 29 gallon bio cube freshwater aquarium with live plants. Its dimentions are 20"L x 20.75"W x 19.25"H with two 36 watt fluorescent 16" lights. The temperature is 86 degrees right now, and I need to lower it but I don't know how. If you have any ideas how to lower the temperature without harming my fish or plants I will gladly hear them.