Pencil Cap Algae, (Penicillus capitatus), is related to the popular Merman's shaving Brush. Growing to a size of about 4 inches, it is highly calcified and will not be eaten by fish or snails, making it ideal as a display piece.
This algae is capable of living under low-moderate light, it will grow strongest in moderate to high lighting. We send Pencil Cap algae that is about 2-3 inches tall. All macros present some risk of going sexual and releasing carbon dioxide into you aquarium. However, the risk of adverse pH changes from the release of carbon from this species is extremely low.