I just purchased a fan kit from a famous online auction. the kit has 3 x 3'' fans wired together and has a temp. sensor. it looks like the fans that come in light fixtures. I am going to mount them on my eggcrate which is like a sceen on top of my tank. right now I use a clip on fan but it's noisey and ugly.I'm hoping the lower profile fans will do the trick. anyone out there using something like this? and also, does the temp sensor really work?