Folks -- ascorbic acid treatment went great. Iron stains lifted like magic.
So I used Poly60 to hold off algae and that went okay. So I started adding Chlorine back and the pool turned iron yellow/brown. So I added a modest amount of ascorbic acid back to the pool and bang, it went away.
I've been struggling to raise chlorine levels without getting the water to start turning brown again. And I've been fighting algae as a result.
What's the trick? What am I doing wrong in terms of bringing free chlorine levels back up without the pool turning funky colors?