Thanks for letting me know.
Gah...I will have to cycle without the help of the sponge then. I only know about the potassium permanganate because an employee at a fish store years ago gave me a tiny baggie of it when I purchased a live plant.
Good news though, the fish store that gave me the sponge carry Endler's. I couldn't believe it when I saw them, the closest I've seen around here are Endler's hybrids and they don't have the true colors or markings. The store even had blue Endler's. Yay!