Well, personally, I'd use muriatic acid to lower the pH. If you are at 8.2, start with 2 quarts of muriatic. Circulate 2 - 3 hours and test again. Since your alk is really high, that's what's causing the problem in trying to reduce your pH. You'll probably have to slug a good bit of acid in the pool before it moves.

Definitely get some Cl in there. It WILL help. I'm consistently amazed at the order of what pool "professionals" tell you to fix the green pool problem. When I was a new owner, they did the same thing to me...add the bleach last, and wait a day between chemical additions. CRAZY! To hit 15 ppm, you are going to need about 6 gallons of plain unscented 6% bleach.

I'd get that acid in there, dribble it around the edge of the pool. Wait about 15 mins for it to disperse and then add the bleach through the skimmer. You should see the green fade as you watch. Maintain 15 ppm until the water is clear. Watch your pH as bleach has a tendency to raise it.

Michael