Help with the brown algae!

[Hookman]

I helped my friend set up his tank around the middle of May. We used LR/LS, and he has a damsel, coral banded shrimp, scooter, and hermit crabs(zebra dwarfs). Brown algae started to grow and the LFS said it was diatomic algae, and that it would disapear. It did disapear from the sand, but now there is a lot on the sides and front. He hasn't done a water change yet, and the nitrates are 40ppm I think. How can we get this to go away, Thanks for any suggestions!
Hookman

 

[HoopsGuru]

I think he could get his nitrates lower, also check source water for extra nutrients and phosphates coming in if he isn't using RO/DI. However, with such a new tank this is not a surprise. The best remedy other than stated above would be patience, as the tank matures nuisance algae blooms should become less and less apparent as more desireable algae gets established and the tank matures. Maybe a few more snails to clean the glass would help too.