Algae ID - New reefer

[Azariah]

Hi All,
I am a new reefer and about 13 days into my cycle so again apologies for the frequent newbie questions.
I have left the lights on according to the red sea reefer instructions but wants to know if I should be doing anything about the brown (what I assume is algae) spots on my rocks.
Will this take over or will it die off? I am unable to get CUC due to ammonia not being at 0 so is it ok just to leave it or should lights be off. If CUC is required what would assist with this?

Any advice is extremely helpful

 

[Sharkbait19]

Looks like the start of diatoms. They will pass eventually, but first your whole tank will be covered. Hermit carbs and snails help with this and most algaes.

 

[Gtinnel]

I agree with diatoms, your tank will go through quite a few ugly stages and that will be one of them.