At the moment, I don't have any lighting on the tank, it does get filtered, indirect lighting through a window during the day, but if anything, I would think it wasn't getting ENOUGH lighting. I did order some snails (really hope they don't overrun my tank, but if they do, I'll get a puffer fish, heard they like snails correct me if I'm wrong). I think I'm going to give it a couple weeks after I get my snails. See what they do with it, and go from there. It doesn't appear to be spreading and if it is, it's not doing it very quickly. I'm acclimating a cleaner shrimp to my tank as I'm writing this, so hopefully everything goes good with it.