How do I get rid of the "black mold" in my pool?

Although sometimes referred to as mold by description, this is more commonly known as black algae.

Because of the nature of black algae, scrubbing the surface prior to treatment is necessary for effectiveness -- usually with a wire-bristle brush, if the surface allows (plaster or pebble).

Most liquid treatments should be applied with the filter running, while some dry chlorine treatments may require a period of exposure without circulation (white plaster pools only).

In any case, adequate pH levels and other water balance parameters should be maintained to ensure proper effectiveness.

Also, because of the high potential for repeat blooms, implementing the use of a preventative algaecide after treatment is recommended.

If treatment involves a metallic algaecide, follow-up use of a proper sequestrant should also be considered.