Hi everybody, I just need to post a quick question on whether the Brown dirty looking things in the photograph below are some kind of a pest. I can't quite tell from looking at it and inspecting the plant close-up. I can say that I keep these in an aquarium, and I try water so I don't think it is debris being blown around from the wind but I don't see legs. Is it some kind of a scale bug? Or is it really just debris and nothing to be worried about?