Did that shelf piece have hair algae to begin with? In general hair algae is normal for newer tanks. Hair algae feeds off of phosphates and I am guessing it came from the new rock you put in which is normal. In terms of cycling, you want to look at the levels aka Ammonia, Nitrate, and Nitirite. Give it a few weeks and all your levels should go to 0. There are some more indepth reads about cycling a tank, I highly suggest the read.
