What is this stuff ??

[sebastiaan153]

Okey so im new to saltwater. My tank is running fine for the last 3 weeks since 3 days i have had this brown/orange stuff growing on the rocks and sand.
My tank is 90liters
All perimters where good except for nitrate.
What should i do ?
Tank is 3 weeks old with live rock

 

[Mr. Mojo Rising]

it looks like diatoms, it is a natural progression in a new tank. It is feeding off the silicates in the sand, and it will die out on its own in a couple of weeks when the silicates are fully consumed (unless you somehow add more silicates to the tank)

 

[FellowSclownfish20270]

Diatoms is a normal stage for a new salt water aquariums! In other words, it can also be called "the ugly stage." Bennie's also enjoy feeding off algae & diatoms on your glass. The ugly stage is not harmful to any of your live stock. After the diatoms are gone, green algae is your next stage.