Dry rock becoming live

[CafeReef]

Question for everyone. My 21 contains about 20 lbs of live sand,14 lbs of live rock, and 4 lbs of dry rock.

How long does it take dry rock to generally become live? What are the signs? Ive got some small spounges and coraline algae spots starting to show on my dry rock. Currently the rock has been in my tank about 5 weeks. They were not cured, straight in the tank (newbie symdrome, didn't know any better).

Thanks

[gavinsepanik]

It depends on many things: light, surface area, amount of bacteria, etc.

[CHizer]

4lbs won't take long. It's probably already alive for the most part.

[Bill Nye]

Depends on what you mean by alive. After the cycle dead rock is officially "alive" but it takes a while for coralline and other micro-organisms to fully colonize the rock.