White on live rock

[new25tank]

I need help with some weird white growth on my live rock. My live rock is covered with it. It is not filmy and it is hard. Some was on my live rock when I got it but it seems to be all over the place. My tank is 48 days old and my water parameters are ammonia, nitrate, nitrite-all 0. My salinity is 1.022-23 (hard to tell exactly somewhere in between), my pH is 8.2, and my temp has been a constant 77F. We have 5 hermits, and 4 days ago we were gifted with 2 percula clown. Everyone seems to be doing just great, I am just worried about the white on the rock. I will try and attach a photo so there is something better than my description. Oh by the way, the tank is 25 gallons, and we are running (not more than 8 hours) a 130W power compact.

 

[new25tank]

Ok the picture was less descriptive than my description. Any ideas will be appreciated. One maybe important note is that I can't scrape off the white, even with my fingernail.

 

[oceanists]

the white on your rock is coraline die off , you need to make sure that there is no dead spots with your flow and also make sure your calcium levels are at about 400 ...... get your calcium to 400 and with your lighting you should see that white turn to green or purple ...... you can also use purple up , that product works wonders

 

[clownfish4]

I have the same thing and only this time it is little round dots of white all over the live rock. And it is not all in one area ether.