Anyone use regular styrofoam for rocks?

[RentaPig311]

Well I came back from the lonestar reptile expo with a red footed tortoise and a renewed desire to update my vivs(not for the redfoot). I began building some more complicated things out of plain jane styrofoam in this thread I ran out of steam and never finished when I failed to find any nontoxic waterproof epoxy resin to finish up the tree. Now I have a bare tree and bag full of "rocks". Anyway I started researching some more on here and noticed that everyone is more or less using insulation foam. I was wondering if anyone just used regular craft store foam like I did and how it turned out? I'll probably have to throw several hours of rock work out because I failed to seal or soak the rocks and used regular floor grout instead of sanded but was hoping to salvage the tree.

[VivariumWorks]

You are fine. The type of foam you use is irrelevant, all its there to do is have support and as long as the design is structurally sound, its not a big deal.

You don't have to use sanded grout. Non-sanded works just fine.

You don't HAVE to seal your work but you will need to let it cure properly or else the caustic calcium hydroxide intermediates will leach into your water/soil and shoot their pH's up to phytotoxic levels. Animals my not get messed up but they plants will for sure.

If you want to seal your work you can use a clear epoxy system from Dewy Supply in Corpus Christi called EpoBond. It works well for this purpose. Google them and call, they don't have a website. You won't need much, a little goes a long ways, bad thing is it makes your work very shiny. I don't use that method anymore personally but it was a favorite of mine for a while.

[SanduskySerpents]

I use it in all my build....from the rigid white to the soft green stuff you can buy a the crafts store....

[RentaPig311]

So can I still go back and soak them or is there a time limit? Also is there a way to test ph?