# 3D Background ?



## Isujustice05 (Apr 17, 2008)

What type of concrete is the best for a 3D background? I've seen so many options from resurfacer to just plain quick setting cement. Also do I need to use a sealer or the acrylic hardener? Done alot of research but seem to get mixed opinions.


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## TarantulaGuy (Apr 15, 2009)

I've built a few dart frog tanks, and what I use is Great Stuff Expanding foam. It works brilliantly as a background, and once it cures, is non-toxic. After you foam in the back of the tank, you can carve it with hobby knives. Then it gets a coating of non-toxic black silicone and you can press whatever covering material (sand, gravel, coconut fiber) into the still wet silicone. Gives you a great looking, 3D background that looks like a riverbank. 

Now, a word of caution. This is used for terrestrial tanks. I can't guarantee that it will hold up under water. There's no reason it shouldn't really, I've built waterfalls out of this stuff that are constantly submerged in water and they've held up just fine. But never tried submerging the whole thing. And you do have to wait a bit for the curing process to finish with each step.


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## ecl (Aug 6, 2012)

a nice simple way is to just get some styrofoam(i used the stuff that came out of packages) you shape it then use DryLok, its a white water sealer, with some cement coloring. it drys fast and no ill affects to the fish. Ive been using one background for over a year now and just made some rocks 6 months ago for another.


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