Wow. This is the 2nd case like this, running right now. The first case didn't get good results till the chlorine levels exceeded 40 ppm, but they had lower CYA levels than you.

PLUS, you've got a concrete pool, so we don't need to worry about making a liner fade. OK, each gallon of 6% household bleach will add about 4.5 ppm to your pool (PF9 x 0.5lbs/Chlorine gas equiv per gallon of 6% bleach).

So, tomorrow evening (or tonight, if you can) add 11 gallons of plain 6% bleach (~50 ppm). If that doesn't have an effect, follow the next evening with 16 gallons. I wouldn't bother with K2006 chlorine testing -- you use up your FAS drops. Just test with OTO -- you should be dark orange after 30 seconds with OTO, AFTER you've added your doses. You might even get brownish, after the 2nd dose.

BUT . . . you need to KILL your algae, not wrestle with it!

And . . . if you are not already doing so, run your pump 24/7.