blue insulation board *inside* the tank

[ewok]

has anyone tried this?

rtr mentioned this in another thread and it hit me....... why not?

i know expanded polystyrene will absorb water and extruded will not. i think the blue foundation board is extruded.... i just saw a home show the other day where they shaped styrofoam to look like bricks for a fireplace. that was expanded foam, but i imagine extruded foam would have the same basic properties.

this sort of goes together with my stacking rocks thread......

so what if? i take a piece of board and sand it and shape it a little so it's not smooth and flat, give it some texture basically. smear it with silicone and liberally dose it with sand. use that as a background behind my rocks.

so then i could stack rocks against the board/back glass too?

anyone see any fatal flaws to my reasoning?

comments?

[TKOS]

The only problem might be if they put additives in the foam for properties like fire resistance and mildew resistance. I'm not sure if they do or not.