First time poster - long time reader.
I drained my pool to acid wash it. I know this isn't really advised but I was trying to get rid of black algae and just couldn't maintain a SLAM long enough to win.
Pool is drained and I've cleaned it with both acid and bleach. This is what the side of my pool still looks like. I think the darker spots are probably still black algae that I just need to attack again. What are the browner parts and what should I do before filling? (As I put in my signature my pool was built in 2005, I know I'm nearing the end of my plaster lifespan.)
Thanks in advance for the help - sorry if I'm missing some needed information.