Protective Layer

• Black algae has a protective layer, which pool chemicals cannot penetrate to kill the organism. You can remove the protective layer of black algae, but you will not remove the roots, which will grow back another protective layer. Removing the algae requires removing the protective layer and the roots, which takes a great deal of time and dedication.
  
  

Equipment

• Cleaning the black algae from the pool requires brushing the spots with a brush. If the pool is fiberglass, gunite or concrete, use a stainless steel wire-bristle brush. Pools with a vinyl liner rip or tear easily, so you need to use a nylon scrub brush. The black algae spots are scrubbed with the brush to remove the protective layer and the roots every day during the removal process.
  
  

Chemicals

• Pools with green algae need shock and an algaecide, but for black algae, you need a metallic algaecide, shock and a metal sequestering agent. Metallic algaecide contains copper, which aids in the removal of black algae. However, copper in the pool can corrode metal fixtures and stain tiles or plaster, so a metal sequestering agent is added after the metallic algaecide treatment to bind the copper.
  
  

Time

• It takes about 10 days or longer to remove black algae from a pool. Each day, you need to brush down the pool walls, floor and steps. The pool is shocked on the first and sixth days during the cleaning process. The metallic algaecide is added on the second day and the metal sequestering agent is added on the ninth day.