Pre-closing water chemistry questions

[pwa2003]

We're scheduled to have our inground plaster pool closed & covered (mesh) in 6 days. I am to have the pool clean and the water balanced, and I'll be adding Polyquat 60, so that the service won't be adding any chemicals.

Here are my latest test results:

FC 8.0
pH 7.8
TA 90
CH 325
CYA 80-90 (I should probably re-test after bringing water to room temp -- just read about that today)
Salt 2700-2800

Water temp is around 47F
CSI on Pool Math comes in at -0.30 based on the above, the very lower limit as I understand it.

Is there anything I should be doing chemistry-wise now to get ready for closing?
Should I add liquid chlorine to bring FC up any higher? It's been hanging around 8.0 for quite some time, ever since the water temp dropped into the 50's and now 40's.

 

[duraleigh]

I would suggest bringing FC to SLAM value (for 80 CYA) just before you close. That'll keep FC in your pool for as long as possible.

 

[Newdude]

From the looks of your extended weather forecast, it's plenty cool enough by you that you can skip the PQ. The options are

1) full SLAM no PQ
2) half SLAM with PQ.

Close with a mid 7 PH. Open at the last freeze either way.

 

[pwa2003]

Thanks for the replies! One more concern: If I lower the pH to 7.6, the Pool Math app shows my CSI would drop to -0.50 (with the warning to avoid going below -0.30 for prolonged periods). Do I need to be concerned about that?

 

[Newdude]

It won't be long term as the PH will naturally rise in a plaster pool with no acid being added.