aquascaping

[hookedonreefs]

OK, I'm ready to pull the little hair I have left out!
I'm trying to arrange my base rock (100 lbs.) and it just isn't working right. Everytime I set up a section I shake it a little and try to add pressure to ensure nothing topples after livestock is added. So here's my question:
How "stable" does the rock need to be. In rock climbing we talk about "bombproof" which basically means it ain't gonna move. But after many attempts I'm starting to think that's impossible. I'm also thinking the amount of pressure I can add won't be equalled by a small hermit crab or other livestock. So what's the basic standard for a stable rock formation?
Thanks for any input on this, as it's been driving me nuts for a few days now.
Also, is it normal for the sand to get stirred up during the process? I usually get about half the tank done, wait for the sand to settle, see that I like the arrangement, then test for stability. Then tear the whole thing down because I can make something move

 

[hookedonreefs]

ahh spelunking.... Probably the best thing in the world.... next to reef tanks
When I was in South Africa I went on a spelunking trip that took 4 hous in and 4 hours out. In the center there was a crystal cavern. The only downside is crawling through water and mud on your stomach which keeps you from bringing a camera unless it's water resitant.

 

[toddpolish]

gettin back to the original post, I'm 3 weeks in and have modified my rock about 2 times since I originally put it in.
Last night I spent 3 hrs moving rock around. needed more tunnels.
I try and get it so that if I push the higher pieces just a little bit to the right/left, it won't fall. Yeah, it might move a bit if I jiggle it, but its secure enough.
one LFS I go to arrange their rock against the back wall. looks like there's more space and I bet that it's secure.
you also could try epoxy.