Adding live rock to existing setup

[Bifferwine]

That's always a risk you run if you add rock after livestock.

 

[RigoSharon]

add small amounts at a time...that way your inhabitants can tolerate the curing cycle of the new rock..and amonia spikes wont be to severe...after that particulary rock is cycled..ad another...and so on..till you have all the rocks you want for your tank..