Is this stuff on my dry rock good or bad?

[KDS]

Been cycling a 75 gallon tank with 50 lbs of dry rock. It's been about 3 weeks and just saw these reddish/brown things on the rock. Also been adding a little bit of "Purple Up" on and off. Is this good coralline algae or is it something that I need to be concerned about?

Thanks,

Kevin

 

[CleverBs]

Do you have rock with coralline algae on it already because yo u need to have it in the tank purple up alone won't create it if you just have dry rock or live rock without coralline algae. By the look of it its just some algae and most everyone deals with algae while their tank becomes a stablished. I had all my dry rock covered in long red slimy algae for like 3 weeks then I put a skimmer on my tank and in 48 hours it was all gone.

 

[FTMMWS]

Probably just some diatoms starting...
The purple up is nothing more than a calcium additive ,and unless you already have some coralline growing it won't make it appear and start growing..It only helps coralline that is already growing to spread more.

EDIT: clever beat me to it