When the filter IS fixed, leave the top open and allow a large cascade of water from the fall, to help cool it down. The more disruption, the cooler itll be. If you have an airstone, shove that in, too- for the same.
And I agree with forbiddensecrets. It really did sound that way. I was under the impression that you were trying to get rid of one for another. Actually- I still am.
Again, no one was being rude. Just trying to help.