There is a stickied thread that talks about closing an AG pool. If you haven't already done so, it would probably be helpful for you to read it.

With a CYA of 70, I would take the chlorine up before you close the pool. Take a look at the Best Guess Chlorine Chart in my signature below. A FC of 4.8 is flirting with algae with that CYA level. (By the way, just use a 10ml sample instead of a 25ml sample when you test. It will save on your reagents.)