Purple/White Moss Exclusive on Honeycomb Rock?

[RonJohnDes]

I have a 55 gallon saltwater aquarium. It's currently cycling and thusly undergoing plenty of changes, it's chemical stats are as follows: PH 8.0, Ammonia 0.00, NO2 0.25, NO3 2.0, SG 1.021, Temp 78*

There's plenty of powerhead circulation, it's sitting on a combination of live reef sand and crushed coral. I have about 25 pounds of cured live rock, 20 pounds of honeycomb rock and ten pounds of lava rock.

A day after dropping in the required dose of PH-Up drops to bring the PH to a healthy 8.2 (it ended up remaining at 8.0), a white/purple moss started growing over all the honeycomb rock, and only the honeycomb rock. It looks like a very thin layer of melted wax, with a white and purple hue to it. It waves in the current, loosely covers the rock yet takes effort to break or blow away. None of the other rocks have a trace of this substance on them, yet after repeated removal, it returns to the honeycomb rock. Is this caused by the PH-Up drops, is it a bacterial reaction? Is it a seperate form of algae or bacteria that's growing? Will it clear? Any help would be extraordinary.

The picture I enclosed shows the honeycomb rock, surrounded by the uneffected live rock. The whitish coating is the problem I'm talking about.

 

[XXFirefighter]

looks like die off to me...
This is base rock u said?

 

[RonJohnDes]

Yeah, it's baserock. Last time I checked, you don't need to "cure" baserock, considering it's lifeless. I rinsed it in water for a good thirty minutes, getting all loose particals/sand off. It's still there and strong as ever, days after the photo.