Black and green spots in the pool

[jamasee33]

We have a pool that we just purchased the home. In the pool there are black and green spots and many black streams all the way in the bottom of the pool. We used Black treat for black algea thinking that is what it was however there is no difference in the pool or stains at all. The pool water is very clear. what could it be?[/b]

[muss08]

Can you feel the black spots if you rub your hands over them? Chances are it is in fact black algae. Even adding a black algaecide may not work espcially if you didnt brush the spots first with a metal brush. Black algae forms a hard protective shell over itself for protection. This shell is very hard to penetrate even for high levels of chlorine and algaecides. A pool I serviced recently had some black algae spots and it took four days of brushing twice a day and shocking once a day with four pounds of granular chlorine. It is VERY nasty stuff.