I had it on my rock centerpiece and substrate. Took the rock out, scrubbed it and baked it in the oven. Decreased my lighting and it has not come back. Even the substrate is almost completely gone. Lighting and consistant water changes, I believe, are the answer.
2 Angels, 2 Aeneus Cory
7 Neon Tetras, 7 Glowlight Tetra
2 Glass Cats
1 Spotted Raphael Catfish
1 Dwarf Bristlenose Pleco