madwill nails it:

If your FC is NOT dropping by more than 1ppm overnight and your CC <.5ppm, you don't need to shock.

Otherwise you do.

Assuming you don't need to shock:
Other things to speed up cleaning your pool can be using "skimmer socks" in your skimmer. They are cheap and work amazingly well. A couple of layers of old panty-hose can substitute. I find the skimmer socks are fine enough to prevent pollen getting in to my filter.
You can also now dose your water with PolyQuat, the only algaecide we recommend. Interestingly, PolyQuat may help clear your water faster as its also a good clarifier. I'd only use an ounce or two, and you WILL see your FC drop over 24 hours, but probably not much.

Carl