I am currently buildind a red eyed tree frog terrarium. I have used expanding foam for the background and for one of the sides. I have a waterfall in the corner that will feed into a small stream leading into a pond at the front.

I am just in the process of preping the backround foam to add eco earth with silicon. Does anybody know if the substrate added to the silicon needs to be bone dry? I had a block of substrate that needed soaking in water to expand and now is a little damp. Any help would be amazing, cheers