I read through about 3 pages of posts over the past few days trying to get a good understanding of all that goes into paludariums. I read alot about people using foam for structures and what not, but at first I sort of blew this idea off and didnt pay much attention to it. Now that Im considering it, I cant find any of the threads I read that mentioned it. So basically what I'd like to know, is what sort of foam is used? Are you using foam insulation that you spray, or would that work? Do I need to find a certain type that isnt toxic, or are they all ok? Are these foam structures durable? Does water or light break them down over time? And when Im spraying the foam, do I make my structure before hand and then glue it in, or do I actually spray it to the tank to form it?