I am in need of advice. I have a SWG and have black algae mainly in the hot tub. It is a relatively small amount. There is also a small amount on the pool wall. I had my water tested yesterday and here are my results.
FAC - 0
ph - 8
I added 27 oz of muratic acid yesterday,brushed, vacummed and back washed. Please advise regarding the best way to proceed to get rid of the algae.