+ Add the polyquat right away, and keep doing so at 1.5x maintenance doses. Get it in RIGHT AWAY; we don't want your pool to turn green, while the chlorine is low!!!!!!!!
+ Add the CYA
+ Run your trichlor tabs, and gradually increase them to gradually bring the chlorine level up, over a week's time.
+ Don't use bleach before then.
+ Use borax if the pH goes below 7.0

Ben