1 gallon = 128 ounces. 2.6 gallons = 332.8 ounces. 2.6 gallons of 6% bleach is what will raise chlorine 13K gallons of water by 12 ppm. I'm not sure I'm understanding your first line of the above post?

You'll have to check the ingredient label on the super shock--if it's cal-hypo, it's not stabilized. If it's dichlor, then it has CYA--enough that for every 10 ppm of chlorine it adds, it also adds 9 ppm of stabilizer.