I have been noticing these very small black 'specks' on my stairs and some on the pool bottom. I have shocked the pool as described and the FC level does hold overnight. (The attached picture is an extreme close-up of my top step)
Are these the remains of black algae? If I scrub them with a stainless steel brush, some do come off but they are stubborn! Any ideas?
Thanks in advance!
Are these the remains of black algae? If I scrub them with a stainless steel brush, some do come off but they are stubborn! Any ideas?
Thanks in advance!
