What is this brownish rust color stuff?

[Salt in Texas]

These are not great pictures but what is the brown rust color stuff on the top of the rocks? Is it something I need to worry about? If I need to get rid of it what's the process. Thanks a ton!

 

[DeniseAndy]

Just looks like a young tank getting some algae. Usually clears up in time to get other types going. Welcome!

 

[PDR]

Agree with the above, normal and nothing to worry about. Most likely just diatoms.