Brown dust- algae?

So when ever I stir my laterite gravel it kicks up a lot of rust colored dust. There is also a coating of the same on the anubias leaves. This stuff also sits on narrow leaved plants, it sticks on to the leaves. Seems like it maybe usurping the plants light space preventing their photosynthesis. So the same stuff is present as dust in the gravel, a thin brown coat on the anubias that can be rubbed off and as smaller specs on the rotala. It makes the rotala look ugly because the leaves have these things on them so they don't look a full green or yellow. I want to see their natural colors. Please help