You don't want to close with algae. With a CYA of 160, chlorine levels of 17 are not high enough to kill it. Go ahead and take the chlorine up to 25. Keep it at that level until you meet three criteria:

1) You lose no more than 1ppm of FC from sundown one evening until within an hour of sunrise the next morning
2) You have no greater than 0.5ppm of CC
3) You have no signs of algae

Then, keep the chlorine high for one additional day and then let it drift down and keep it between 8-15 ALL the time.

Also, run the pump 24/7 while you are clearing the pool, cleaning the filter as needed.

http://pool9.net/cl-cya/