Rock placement and stability?

[peterthegamer]

I have been adding a few pieces of LR to the tank and seems like it's kinda stable yet not sure if I should add more or less. Finally today I saw a one of the pieces shift an inch or two, wondering if I should reconsider, adding epoxy to hold it better.
Also should I add a blue or black background?
Don't mind the livestock right now, holding it for a new tank.

 

[Oscar47f]

i would go with a black back round but thats just me... and if you don't feel comfortable with your rocks moving some epoxy or glue or reef welder won't hurt at all, it'll give you some piece of mind at least... i warn you epoxy may make the skimmer go crazy maybe try the reef welder stuff its a plastic and is inert meaning no crazy skimmer..