Need help with starting chlorine after drain/refill

Thanks watermom - so I read the sticky and we were about the close the pool this morning but I have run into a problem that I need help with.

Yesterday morning I tested the pool - my FC was 14 ( I was raising it before closing to kill anything in it), my CC 0, my pH 7.3, alk 60, CYA btw 70-80.

We added about 2 lbs of baking soda to increase the alk before adjusting the pH yesterday morning and vacuumed multiple times.

yesterday afternoon I added 28 oz ( less than the quart that Carl recommends in the sticky) of polyquat and put the filter on whirlpool which seems to be my equivalent of recirculate.

I tested just now before starting to drain and stop filter : FC was down to 7.5 but I am OK with this since for my CYA I should have btw 5-10 FC and we will be putting on a solid cover here in Massachusetts. I expected some decrease due to the addition of polyquat - as was mentioned in the sticky as well.

My alk was now up to 70-80 BUT my pH was through the roof - above 8 - so purple I dont know what to call it on the taylor reagent test kit I have - the one you all recommend.

Why has this happened? I can't understand it unless the polyquat did it or the whirlpool did it or something else bad is going on in the pool. I did add more than double the dose of polyquat. do I need to drop it with muriatic acid before covering the pool or can I just cover and deal with it in the spring?

Thanks. acaim

I don't know what effect, if any, the polyquat would have on your pH, but the whirlpool should have caused a great deal of aereation, which will raise your pH. I would drop it down to 7.6 or so, and then proceed with your closing.