The Extensive Health Benefits of Methylene Blue

Go buy some ascorbic acid from the store and put it on the MB stain. Comes out, just get it slightly wet and let it sit awhile. I think I used peroxide too.

I had a bottle from a fish store that had some crusty MB on the top of the bottle. I didn't think anything of it when the MB flake fell on the counter. Later when it was exposed to water (didn't immediately see it), I figured out my mistake.