First let me start by saying that I inherited this pool and most, if not all of the pitting was there when I got it. But it could have gotten worse in the last couple years.
I have some pitting and some etching going on and now they appear to have a black color to them. I assume this is residual algae but I'm not sure. (I had the current limiter recently quit on my SWG)
What causes this pitting and can anything be done to repair it in the short run? (Absent a plaster job) I think my CH is fairly low, but was at a good level last year. I'm in search of the right thing to add, from the right place.
Is the black stuff algae? And how can I get rid of it? I've tried scrubbing and pressurized water. It helps a little, but not much.
I know my CYA is a little low and my TA is a little high, I'm working on getting those in check now. All advice is appreciated!