Koralia/Tunze magnet
 

I was wondering if anyone knows if you can put the magnet that fits on the outside of the glass to hold the powerhead in place, in water? I was wanting to attach a powerhead to my overflow, so the magnet would be sitting in the water. I was considering the Koralia or Tunze.

I do that with one of my Koralias in my sump. Hasn't been a problem.