Jack's Magic The Blue StuffJack's Magic's The Blue Stuff gives pool owners a powerful stain remover designed specifically for plaster pools to control plaster dust, yet gives up none of its cleaning strength. The Blue Stuff is effective at removing copper, iron, and manganese from your pool water, and will work in even high chlorine environments without breaking down. This solution will prevent and remove stains from plaster, vinyl and fiberglass pools safely and quickly,