What is this orange residue!?

[jenp]

I have had my 55G tank with live rock for a couple of months now, and in the past week or two, it has become covered with a deep orange-brown (Color of rust) residue, specifically on the top surfaces of the rock. Some is also forming on the sand bed and walls of the aquarium. What in the heck is it, and what do I do!? Any help would be appreciated, I am new at this and just don't know what to do! Thanks.

 

[9supratt4]

Diatoms possibly??

 

[noah's nemo]

Originally Posted by 9supratt4
http:///forum/post/2784691
Diatoms possibly??
Thats what i was thinking.Seeing as how its on the sand too,then thats probably what it is

 

[cranberry]

Diatoms.....

 

[jenp]

That's exactly what it looks like. Thanks for the quick replies! Glad to know it's not something crazy!

 

[beth]

Or cyanobacteria. Take a look:
https://forums.saltwaterfish.com/t/73002/how-to-rid-your-tank-of-red-slime