PH Control during the winter

[Johnl]

This is a great forum and I'm appreciative of all of the help. I'd like to get your ideas on maintaining a safe PH during the winter. Last year, I opened the pool to find the PH over 8 and scale covering the pool (it was bad...cut your feet bad).

Anyway, thanks to a better test kit and the pool calculator I think I have a handle on maintaining the PH at the proper levels while the pool is open. You should know that we have hard water, so my hardness is normally over 350 (currently at 375). As a result, I have been running my PH lower than the officially recommended 7.6. It's at 7.1 now because I am lowering the Alk.


My current numbers:
Cl - 2.0
Alk - 130
PH - 7.1
CH - 375
CA - 50

Last year I closed the pool with the PH around 7.5. Given what happened, I will probably close it with a lower PH. Does that sound right? Any thoughts or ideas you have to prevent high PH and scaling over the winter would be appreciated.

Also, I have a hard cover that is on all winter. I also bought some Scaletec to add before closing.

 

[duraleigh]

Do you know what the pH was when you closed the pool last year?

 

[Johnl]

It was about 7.5 when I closed the pool and at least 8.0 when I opened it.

 

[duraleigh]

So, it's rising on it's own over the winter. (somewhat unusual)

Since scale is a huge problem and, apparently you close the pool for the winter (you don't say where you live) and since your CH seems to be an unavoidable part of your scaling problem.......all that's left is to control your pH even with the pool closed.

Yes, I would close @ 7.0 or so and I would make some plans to get muriatic into the pool over the winter. It is possible to dilute it down pretty good in a 5-gal bucket and distribute it with a submersible pump and I think that would be easier than the scale removal process.

How did you remove the scale last time?

 

[Johnl]

I live in southeastern PA so the pool is closed October through mid April.

As far as getting the scale off. I bought some Scaletec and a wire brush. Unfortunately, neither of them was working very fast, so I got a metal scraper and started to scrape the sides of the pool. That's where the sharpest scale was. It was a ton of work, but it got most of the scale off. At least to the point where it wasn't cutting you if you ran your hands or feet along the sides. Anyway, I am still brushing and adding Scaletec. I plan on adding a full 1/2 gallon before the pool is closed.

Prior to the scale problem over the winter my plaster was smooth like glass. I don't know if I'll ever get it back to that point. I just don't want it to get worse than what it is now, so the winter maintenance has me a little concerned.

As you stated I plan on closing the pool with a lower PH than last year to see how that works out.