I need a prognosis on brown/ red!

[mikewest]

I have been seeing this brownish stuff on my sand is, and I would like to know if it's going to be bad for my fish or anything? If it is bad If I could find out how to fix it that would be nice!

 

[mikewest]

I have been seeing this brownish stuff on my sand is, and I would like to know if it's going to be bad for my fish or anything? If it is bad If I could find out how to fix it that would be nice!

The picture!

 

[Maya]

Looks like diatoms.