How To Get Rid Of Blackspot Algae In Your Swimming Pool 13 Steps

Other alga species that are common in pools are green algae, mustard or yellow algae, and pink algae, which is actually a bacterium. Algae tend to bloom in pools that have poor circulation, poor filtration, a high pH level, and a low chlorine level. [2] X Research source

Calcium hardness should be tested monthly, and the ideal level is between 180 and 220 parts per million.

Calcium or lithium hypochlorite Granular chlorine Potassium peroxymonosulfate

Use a steel brush for concrete or plaster pools. Use a nylon brush for vinyl, fiberglass, acrylic, or painted pools. [9] X Research source

Black algae have deep roots that work their way into the walls, grout, and filters in your pool. If the roots aren’t destroyed, the organism will continue to grow back. Try rubbing the algae spots with a chlorine tablet after brushing.