What's wrong with my live rock?

Today is day 4 of having live rock in our new 90g tank. About half of it is cultured rock from Florida & has (had?) coraline algae on it. Tonight I noticed that white patches are showing up on the rock where it used to be pink.

Does this mean the coraline is dying? We've had the MHs on for about 8 hours per day. Should they be on this long? On at all?

Thank you for any help you can provide!

 

Same thing happed to me while my Live Rock was curring. I also ran my lights to minimize it, but 75% of the coraline turned white....the good news was that after the curing is done, mine started getting color again. After 10 weeks about 1/2 of what had turned white now has color again.

 

Is your tank still cycling? Probably die-off from the amount of Ammonia, etc.. is killing it.

 

Yes, it is still cycling......does that mean there's nothing I can do to prevent it?

 

What are the levels in the tank? Was the rock cured i.e. did you get it from your LFS or was it shipped to you. Skimmer working well? Try keeping the lights low for a few days so the rock can cure. New rock that is not cured should have low light levels due to the fact you can shock the algae and basically kill it. When a can would come in we would keep her in the dark for 2 weeks and gently start adding light well that was back in the day when you would buy LR that was fully covered.

 

I forgot to mention that it is already cured.

 

its dieing off nothing you can do about it, it is becuase your system is so new, it will grow back though, nothing to worry about

 

Shut the lights down for a bit maybe a few hrs per day, Are you running a skimmer?

 

We are not running the skimmer yet. Do you think we should only have the MHs on for 4-5 hours per day?

 

well there is your problem, cut the lights down I asume you have no coral in the system so this should be fine. 4-5 should be fine but get a SKIMMER I live and die by mine.