Phil,

They CYA test takes a little getting used to.

While it's building in your pool and while you're getting used to the test, 7 TOTAL lbs of CYA should get you into the 60-70 range.

Find out how much your builder put in and add that to what you put in and then be patient. Those few pucks will have little affect. Could some of it have been backwashed out?

Yeah, chlorine demand will be reduced as it cools off.