Algae

[dhbrk]

What is the reddish brown stuff that appears in the sand and on the glass of my reef tank? And what does this mean?

 

[jacksonpt]

It's probably a type of algae, and it's normal for new tanks. It means your system is still trying to balance itself out. You've got too much of something, and the algae is the reaction.

 

[aqua_man]

I had that also during my cycle. Once my phosphates were removed and my lighting was upgraded it went away. I beleive what the reddish brown stuff is "Diatoms" or dead diatoms not 100% sure.

 

[carrie1429]

The diatoms (brown algea) means that your tank has nearly finished cycling and it will go away on its own or with a clean up crew.