My aquarium has a brown silt what is it and how do i get rid of it?

I don't over feed my fish and the silt has been in there every since I established the tank. I have a large piece of malaysian wood that I think might be the problem but im not sure. I don't think its an algae because it isn't getting any worse but it is everywhere the stuff sinks to the bottom and anytime a fish kicks it up the small silt particles go everywhere and it looks ugly. I want to get rid of the stuff anyone know what it could be or how to get rid of it?