aquarium back drop

My question is I have been seeing alot of back drops built out of styrofoam and coated with cement, but all of the ones that I have seen have been used in fresh water not salt, can this been done with salt water and what do I need to look out for by using cement, and color pigmant to acheive the color of rocks??

 

I think unless strapped down, they would float.....

 

they silicone it to the glass and seal all of the outter edges

 

ahhh very cool! I've seen them and there are some that are gorgeous and you could probably make one that will hold corals too....hmmmm:thinking2

and portland cement, you can add crushed coral or even oyster shells or (live) sand. not play sand...

 

If I ever did a nano, I would do one of them. Someone on here did one a while back and it looked pretty cool.
http://www.3reef.com/forums/i-made/foamback-reef-tank-57314.html?highlight=making wall

 

Heres a link to where I saw a real cool one, this is what got me thinking. Make Your Own Background From Styrofoam (DIY DECORATION PROJECTS)

 

That was a cool one. I have never seen anyone carve the entire wall into stones. If they could make it look more reef like that would be slick. You got to remember that if you dont have any live rock then you will need to step up the filtration.

 

I have 85 lbs of live rock along with the other equipment listed in my signature

 

that was awesome! wow gives me some really good ideas for when I set mine back up!(the make your own.....)

 

So does anybody see anything with the cement or color pigment that I need to worry about, so it will not crash my tank?