The one I make for mine will be somewhat different in that I will be making mine verticle rather than horizontal because I'm puttin it in a 48 corner tank. I'll also be changing the standardizaton of the cave entries and the orientation. Between each column I plan in putting some staggered "shelves"... the to finish it I'll be using a mixure of sand/gravel. The shelves will be used to hold Java Fern or what ever else I can anchor there.. Perhaps use some screen shelves between the shelves for mosses.. Now I gotta research some mosses! Yea! But first get the 55 up, relocate the 29Bow to make room for the 48 Corner!
Bill in Va.

almost left out the LINK! http://www.duboisi.com/diy/BNdiygrotto/bndiygrotto.htm

My type of DIY project. Can't wait to see it.

Very cool!