Brown layer on live sand

[Edward2788]

I've had my tank for 2 months and now there is a layer of brown things on my live sand. What is it? How do I get rid of it?

 

[Ingy]

google pics of diatoms. Its a bacteria that eats silica in new tank systems. Normal, natural and usually unavoidable. Some snails, conches and crabs will eat the bacteria and they will eventually go away after all the silica is consumed (a few months).