I think I have decided to make that piece for the bottom of the tank. I still have to make up the sides and back. I will probably use colored grout then a little acrylic paint for details. I might go ahead and use watered down modge podge (i think) and put a few coats to seal it. I probably wont get to work on it until tomorrow night, so I still have a little time to attempt to plan some of this out.