Hi, I am new to all this. I am looking at building a 90 gallon reef tank. I live a very cold climate, 47 below zero is fairly common. Because of this I don't own an ac. It gets up to about the mid to upper 80s a few days a year. I am wondering if this will be a problem with my tank overheating, and what could I do besides running a chiller. Would running normal box fans around the sump work? Any help would be appreciated. Thanks in advance.