Using travertine for substrate instead of none or sand.

[my2rotties]

I appreciate the answers. I did read it was okay to do so, but it is always better to ask real people. I am glad that so far it seems great. My husband is still putting the marble on the background and using his tilesaw to cut liverock into the wall. This is the most fun I have seen him have using his skills. No mortar or grout, just silicone and and a saw. This whole project has been a long time in the making between me being hospitalized after I bought this thing, and many false starts or just no time...

Thanks again.