Black algae in pools can be extremely difficult to kill. Trying to brush the algae with a nylon brush just won't work. The outer covering of black algae forms a hard protective shell. This shell even protects the black algae from high levels of chlorine when shocking or slamming. You're going to need an algae brush, an algaecide and lots of time. If you don't get the results you want, don't get upset, get JB. We'll do all the work. It only takes one call 850-625-9750. Do you want to keep it clean? Learn about our Grande Pool Services.