Is this diatoms in my quarantine tank?

[Bthomas]

This is a quarantine tank I set up beginning of September. Added some corals to it a couple weeks later and all was fine for a month or so then this brown algae showed up and things went south quick. The corals started looking really bad so I moved them out to my display but was wondering what to do about this tank. Is this diatoms or something else? If I leave the tank empty will it run its course and be ready for corals once this clears up? At the moment I'm afraid to put anything else in here

 

[Billldg]

It looks like new tank algae to me, aka the ugly stage.

@ReefSquad

 

[Bthomas]

Would that cause corals to not do well?
If I leave the tank empty will it sort itself out?
Snails arnt touching the stuff either. I have a turbo and 2 trochus in there