How stable does live rock have to be?

[Shocked]

Rearranged my live rock the other day. I haven't done this in three years and I honestly don't remember how much attention I paid to it then:

Exactly how stable does it need to be? For whatever reason, most of it flips and flops when I touch it. Have the big pieces on the bottom, medium in the middle, etc. Only thing I did differently was clear the sand out from beneath it.

I was able to build basically a wall with this rock the last two times I did this, but here it wound up more of a mound and I'm still not really satisfied.

Time to break out PVC pipe and underwater epoxy?

Trying to find some aquascaping videos on Youtube but none all that helpful so far.

[Frantz]

I do my rock all loose. I don't like when it teeters as you are describing as the risk of a fish knocking something on to it and causing a bad chain of events seems too much like tempting fate. I always make sure the base rocks are in contact with the glass, that way they can't be undermined, and I save some big long rocks for mid range for some spans for arches/caves. If you've been happy in the past you should be able to pull it off again, perhaps look at old pictures and see what elements really made you happy before and design them into the new layout

[Scutterborn]

I would never keep a loose rock in my tank. Too many unforeseen variables in dealing with potential hazards.

I mortar all my rock together.


-Ben-

[Shocked]

I do my rock all loose. I don't like when it teeters as you are describing as the risk of a fish knocking something on to it and causing a bad chain of events seems too much like tempting fate. I always make sure the base rocks are in contact with the glass, that way they can't be undermined, and I save some big long rocks for mid range for some spans for arches/caves. If you've been happy in the past you should be able to pull it off again, perhaps look at old pictures and see what elements really made you happy before and design them into the new layout
For whatever reason, I don't have any shots of my previous rock layout. All I have is closeups of fish. That was probably pretty dumb of me.

I did try to build it against the back wall of my tank, as I've done in the past.

Only thing I think might have helped last time was the rock on the bottom had sand to dig into, which gave me a stable base to work with. I didn't do that this time because I read about burrowing critters causing stability issues. Irony, huh?
I would never keep a loose rock in my tank. Too many unforeseen variables in dealing with potential hazards.

I mortar all my rock together.

Can you take it apart if you ever decide to re-do it? Is it just epoxy, or something more complicated?

EDIT: Guessing something like this stuff:

http://www.marcorocks.com/bondingmortar.aspx

Though, was hoping for something less permanent.

[Scutterborn]

Yes. I used Emaco r400 and acryl. The mortar is stronger than the rock. Lol. I did do it in sections for ease of removal/installation.

Here's a few pics.
http://img.tapatalk.com/d/13/06/03/u9ejupur.jpg
http://img.tapatalk.com/d/13/06/03/sumemu3e.jpghttp://img.tapatalk.com/d/13/06/03/yqu6u9uv.jpg

These are older pics from when I set up my tank.


-Ben-

[Shocked]

I think one of my problems is I have way too many bits and pieces. This is how it turned up the other day:

(And yeah, I've since cleaned my glass :lmao: It gets pretty bad when your stuff is down for a long time and you stop doing that kind of maintenance)

[Shocked]

So, I redid all my rock (again), this time with epoxy. It's sitting on a 1"+ sand bed - in hindsight I probably should have run out and gotten some egg crate, but it would be a little hard to start over at this point.

What are the chances burrowing critters would still cause any problems? Not sure how strong this stuff is.