Maybe Algae?

[dancin76ersgurl]

I've had my tank since August and I do weekly or sometimes every 2 weeks water changes. Recently I noticed the rocks in the fron are turning a brownish color and on the front glass there is a patch of brown. I am thinking it's algae...I don't really know. If it is, how can it be cleared up?
O yeah... I don't have any living plants in the tank either

 

[Silly me]

since there is no life plant in the tank you could turn the light off for a week or two, all the algae will go away, even brown algae..
You could also get some algae eaters, but low light condition with free nutrience in the water will make a perfect climate for brown algae to settle..

 

[George Farmer]

Otocinclus sp. love to eat brown algae!!

 

[NickT]

Otocinclus sp. love to eat brown algae!!

they shure do! i just got one of those lill guys in my tank but he needs his school.
if you have the room get 3 so tehy can school.

 

[Da_Oz]

Add some plants to eat what the algae is eating to live. Plants are great for tanks and fish.