Several months ago I had a severe algae issue in one of my tanks. It covered everything including my Marimo Ball. Since peroxide can kill algea, I decided to give it a dip in diluted peroxide My Marimo Ball died. (See where this is going?) Of course peroxide killed my marimo. It is algae! Duh! I knew that! :;smack We've all had a duh moment (or two or more) Anyone want to share theirs?