Title says it all. I'm hoping someone can ID what is going on with my plant.
I purchased an Anubias about 3 months ago and have it in a 5 gallon solo aquarium. I do not dose Flourish and I do not use Co2, and use the standard LED lights that came with the tank.
I'm noticing on all but the newer growths and leaves that there's this powdery growth darkening the leaves. It almost looks as if the fish food is collecting on the plant leaves or something but when I try to rub it off it still leaves like a dark grayish brown residue. I've never seen this before but the plant is growing fairly well and all of the new shoots look perfect. I've attached photos of the older leaves and the newer ones to compare but can anyone ID what is going on here?