I am currently setting up my new tank and put some new live rock in it. The big piece is 56 lbs. and was kept in an unlit tank at the LFS. After a week of increasing the lights by 1hour a day some brown diatoms started growing which I expected. Yesterday I came home and the big rock was covered in 1" to 2" brown hair algae, the smaller 20-25 lb pieces just had some diatoms on them. Does any one know if the algae will go away.