Pool Water Temp Effect on Winterizing Water Balance

[pcranmer]

I am in the process of closing my pool. My current chemical levels are as follows

FC 10
PH 7.4
TA 70
CH 280
CYA 70

22k gal, Bleach, Gunnite (pebble finish)

TA is a little low, but others are within acceptable operating range. I wanted to understand if the water temp should effect my approach to winterization. Under normal condition water temp 78-80 degrees the water has a CSI of -.26 When I lower the water temp to 56 degrees on the Pool Calculator the CSI drops further to -.46. Is this something to be concerned with during the winter months even though the water balance is with in operating levels? If so, should I raise the TA some and then raise PH to counter the water temp drop?

 

[benavidescj]

You should always maintain your CSI close to 0 even in the winter months. When the water starts to get colder the pH should rise some to compensate. So what you are saying is right, adjust your TA and pH to compensate for the colder water.

 

[257WbyMag]

As long as you don't allow your CSI to go lower than -0.6 for a period of time, you should be okay. What I typically do is let the pH stay a little higher during the winter. I'll let the pH sit around 7.7 or 7.8 and things stay fine.

I see no problems with your TA.