# DIY rocks



## seamount (Jul 3, 2014)

Hi,

I am thinking about making some DIY rocks for my DIY 3D background. My question is how to I get them to stay down? I dont really want to silicone them to the bottom of the tank because then I won't be able to move them. Any ideas? I could fill it with something heavy? Other rocks? Going to coat with drylock and cement color from quikcreete.


----------



## dalto (Aug 20, 2006)

You could put actual rocks inside your fake rocks.


----------



## Kanorin (Apr 8, 2008)

Or just put the same shade of drylok + quickcrete painted onto some real rocks.


----------



## delta5 (Jul 5, 2014)

Maybe line the back glass with rubber or whatever to protect the glass and then stack the back with real rocks? You can use an impact driver to drill holes deep enough to connect the rocks together with some sort of waterproof dow pins. If your water isn't naturally high enough in ph you'd benefit from limestone or other rock that raises the ph.


----------



## Mcdaphnia (Dec 16, 2003)

You can make them from waterfall foam. It is porous when cured, so it absorbs water and sinks. If you paint it, leave the bottom and back uncoated so it can absorb water and sink.


----------



## Mcdaphnia (Dec 16, 2003)

And there is this video. It might help with ideas, even though it's a commercial. http://www.pondarmor.com/creating-faux- ... ms-part-1/


----------

