Thinking of building a rack. . . Where to put Tstat?

Hi all! I'm thinking of putting together a small 2/3 tub rack. I was just curious: where do you attatch your thermostats? Pics would be awesome. Thanks!

Well if its the proe you are talking about... I attach it directly to the heat tape...

As for the t stat itself... I have mine hanging on the wall right behind my racks.

Yes it was the probe I was talking about. What if the tubs fit too snugly in the rack. Where is there room for the probe?

Usually between the tubs there is just enough space... At least there is on my racks...