I wouldn't go to 30 if your CYA is 50-ish (don't know how you got 53 because the tests are way more subjective than that). It wouldn't hurt to go up to 15 just until that CC is gone. Make sure that you're backwashing the filter as your pressure indicates. You didn't give a reading for CH--if it's high, and the "granulated shock" you used was cal-hypo, then that may be the reason for some of the cloudiness. If the pool was really green before the shock, that's probably part of the cloudiness, too. If it's dead algae, then you should start to see some improvement before long. If it's calcium being too high, then the water will probably stay milky looking until you either partially drain/refill or drop your pH and alkalinity.

Janet