Foam and Grout question

[Shandley]

Greetings,

I have a quick question. People are building their hides and walls with (and I know it's a brand name but for lack of a better word) Styrofoam. Can this be any Styrofoam?

Also, people are painting on grout before sealing with a non toxic sealer. Again, is this just good ole regular tile grout?

 

[houseb]

I can't speak for everyone else, but when I built my rock wall I simply used polystyrene (styrofoam) insulation from Home Depot. This is what it looks like:

I used non-sanded white grout (it's the cheapest) directly on the foam then painted it with acrylic paint. I used non-toxic sealant as my last 5 coats. A good website with instructional vids and explanations is http://www.lizard-landscapes.com/

I know some people use cement instead of grout, but I think the curing process is long and complicated, but there is someone that explains it on the cichlid forums:http://www.cichlid-forum.com/articles/diy_aquarium_background.php
Hope this helps

 

[Franklinj480]

http://www.lizard-landscapes.com/ is the website that I used to guide me,

Homedepot carries "Polyblend" non-sanded grout, as for non-toxic sealer I used "Mod-Podge"