Need Help with this brown algae

[emmi]

when i first set up my tank a few months ago, it didn't take long before i noticed some brown spots appears on some of the decor . almost looks like rust.

Now i'm noticing the brown spots are back on the glass in the tank. it's spreading rather quickly. It look like hair
what is it????
is this a danger or risk for the fish?
all my water tests ( ph / nitrate/nitrite/ammonia) all come out just where they should be.
I change the ligth bulb i bought lately two SAE ...and mollies
hope it will be worth it
many thanks.

I have a 55g tank

 

[Guest]

How much light do you have over the tank? And a picture of the algae would help. Normally brown algae is diatom algae and some Otto's will clear it up in nothing flat. But diatom algae isn't hair like.

 

[betowess]

Sounds like brown diatom algae which is perfectly normal in a new tank and perhaps hair algae, simultaneously. Eventually the brown algae will go away being replaced by green algae which competes more efficiently for nutrients. Everything is cool. 8)

Like Rex said, Get some Otto cats... For your size tank, five or six would be perfect. The little buggers are great fun to watch and very active swimming all over the place together, No planted tank should be without them.
for Hair algae SAE are recommended, I think? HTH Betowess

 

[emmi]

well thanks a lot
I think that i the answers i needed.

it is true i noticed a formation of green algæ over the brown which is vanishing rather slowly.........

thanks....