Also, you can apply vasoline or something else that will make a waterproof barrier to the filter, and then apply the GS, let it cure, then pop out the filter (if you don't want to have the filter BEHIND something). I just made a mold with a bowl for some hides for my BP, and I did this, it worked just fine. Take a look at the
http://www.vivariumforum.com/communi...kish-crab.html, in there she talks about how she did her filter in a similar way to what I am talking about. Using this method gives you more options, I think.