Try using some fans for now ,that should help ,It is still a cool breeze so it should cool the tank down .Use a cntroller so you wont over chill the tank .If you have an AC you can use that and the fans for the summer ,keeping you and the tank cool.I find that cheaper then letting the chiller go on and off every hr . Having a chiller as a back up is a must if you ask me .I have my ac on all summer long and fans controlled my by RK2 as well as the chiller .