Well, its that time of year again! The heat is back and my tank is getting hotter than it was last year. The fluorescent lights I have on in my room all day probably aren't helping, but you could always blame global warming.

(jk)
Is there some kind of simple way I could cool down my tank? (5 gal.) I was thinking about putting an ice pack around it for a minute or two, but then I realised the temperature would stay cold on one side and hot on another.
I really don't want to buy a chiller...
Thanks for any ideas!
-Matt