Help! Rock discoloration

[scarroll0466]

Hi, I noticed my rocks becoming a bit discolored over the pst couple days. I have (2) arctic t-247 running 5"above water. Ch 1 is set to 40 and ch 2 at 45. The frags seem to be doing great, any suggestions?
Thanks

 

[Diesel]

It's normal!
Welcome to the amazing world of the reef hobby

 

[scarroll0466]

That's a relief! Thank you!