Closing done.. but is my PH too low?? Pls help clarify the winter chemistry !

Jump to latest Follow Reply
MostlyCanuck

MostlyCanuck

Bronze Supporter
Mar 19, 2021
186
Toronto, Ontario, Canada
Pool Size
15000
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Big thx for all the advice on the forum. Closed the pool on my own and feel really good about the process!

I left my PH at 7.2, as I read (at at least I think I understood) from a few posts here that over the winter with cold temperatures PH will increase, and therefore to start at lower end of the range. However, I read on several sites the exact opposite - i.e., that in winter closing it is recommended to close the pool at higher range (7.8) because during the winter the stagnant water will naturally decrease in PH..

Did I misunderstand? If so I can always dump a bucket of borax to raise it and throw a pump in to circulate it...

Thx a lot for your science-based advice here... I am very confused on this point..

ps - I'm in Canada and winter temps will drop very significantly here...
 
Last edited:
You have a vinyl pool. The comments about pH rising over the winter are a characteristic of plaster pools. Especially plaster pools that are only a few years old and still curing.

However pH only decreases through adding acid. I don't know what chemistry those sites you are reading think is going on.

Your pH of 7.2 should be fine. Any pH in the 7's is fine for your vinyl pool.
 
  • Like
Reactions: Mdragger88
While I wouldn't worry about the pH you're reporting, there are certainly OTHER factors involved (such as the total alkalinity) which also affect the inevitable pH rise over time due to, at the very least, carbon dioxide outgassing (of course that depends on the amount of aeration/agitation).
 
What kind of cover are you using ? If it's permeable, the rain and melting snow getting through has a Ph in the 5s and will lower you substantially over the off season.
 
Newdude said:
What kind of cover are you using ? If it's permeable, the rain and melting snow getting through has a Ph in the 5s and will lower you substantially over the off season.
Click to expand...
it's a mesh cover. I hadn't thought of that at all. so, yes - better to put it back in the high range at 7.8 or so perhaps if what I can expect is dropping PH during the winter. would you agree?
 
MostlyCanuck said:
better to put it back in the high range at 7.8 or so
Click to expand...
Yes, but that's easier said than done with no pump. I'd let it ride this year, being no worse than many other pools out there, and next year close it higher in the 7s.
 
Newdude said:
Yes, but that's easier said than done with no pump. I'd let it ride this year, being no worse than many other pools out there, and next year close it higher in the 7s.
Click to expand...
looks like to get my pool from 7.2 to at least 7.6, I'd need about 2.6 lbs of borax. not sure how many gallons of water that needs to be dissolved in (never used borax before), but I could go that way with 5gal buckets and use my submersible sump pump to circulate the water in the pool. wouldn't that work?
 
MostlyCanuck said:
wouldn't that work?
Click to expand...
It would (y) Hit as much as you can with the brush when youre done mixing. You can brush surprisingly far with only a small part of the cover open.

I never needed to do it without the pump but I'd do the 2.6 lbs in thirds or quarters in a 5 gallon bucket. Just because.
 
  • Like
Reactions: MostlyCanuck
Quick update for posterity - should anyone else need to address a similar situation, the fix was super easy. Lifted up a corner of the cover, dumped my borax (2.6lbs in my case) into the deep end (well pre-dissolved into two 5gal buckets of water), brushed the area, put in a sump pump to circulate the water for maybe 10 min... a few hrs later I tested both at the deep and shallow end - and my PH was reading a clear 7.6 both times. Really not a challenge.

I guess I could have brought it up to 7.8 if it does drop significantly with rain and snow melt as Newdude suggested - but I didn't want to over-adjust with borax in fear I would add too much... and now that I'm at 7.6 I feel okay and don't want to tinker again!!

Thx all for the advice
 
  • Like
Reactions: Newdude

Enjoying this content?

Support TFP with a donation.

Give Support
MostlyCanuck said:
my PH was reading a clear 7.6 both times.
Click to expand...
Why are you directly "aiming" at the pH instead of aiming at the saturation balance (of which pH is just one component)?

I'm trying to better understand the winter closing process for outdoor pools that are unlike mine (mine is plaster with no cover & rare freezing temperatures).
Yours is vinyl with a cover (and colder expected temperatures for longer periods of time).

For saturation, pH is just one component of the saturation which itself is comprised of about a half dozen components.
Calcium Saturation Index (CSI)

As I understand the winter closing process for outdoor uncovered plaster outdoor pool, pH in and of itself, is not a meaningful attribute as it doesn't have any meaningful effect on sanitation and its effect on saturation is a secondary byproduct of the natural pH ceiling which itself is mostly due to carbonate, bicarbonate, and hydroxide alkalinity.

Hence, for an outdoor plaster pool that has no cover, I wouldn't even think of aiming at the pH - I would aim at the balance mostly between TA & CH (where, of course, the TA affects the natural pH ceiling just as borates affect the natural pH floor).

How different is a vinyl pool for that purpose?
And why add borax?

Borates in pool - Further Reading​

From what I can discern in this thread, you're using borax to set the natural pH floor, and you're aiming directly at the pH. But why?

So you want to add borates to your pool--Why and How​

I'm confused, but maybe things are different for closing vinyl pools than plaster pools in the regard that you don't aim at the pH when closing an outdoor plaster pool because you aim instead for the (more complex) saturation balance over the expected temperature range when closing a plaster pool for the winter season.
 
Last edited:
Gary Davis said:
I'm confused, but maybe things are different for closing vinyl pools than plaster pools in the regard that you don't aim at the pH when closing an outdoor plaster pool
Click to expand...
Low PH (in the 5s) can wrinkle vinyl liners like a fingerprint with 1000 little guys going everywhich way. So much so that you can't just pull one or two out like you might be able to if the wrinkles were from the liner floating from ground water.

Knowing that the rain will lower the PH over winter with a permeable cover, it's not a bad idea to close on the higher side of the PH range. @MostlyCanuck had lowered his to start and chose to add some wiggle room.
 
I’d really like it if the rain and snow lowered my pH over winter but mine has been crazy high when I open back up in March. Has anyone verified that the pH actually does drop down?
 
Bperry said:
Has anyone verified that the pH actually does drop down?
Click to expand...
YMMV of course, but I found that mine was always bottomed out in the spring. One year it wasn't and the lady at the pool store laughed and told me that I must have discovered baking soda so I wouldn't need to buy their expensive stuffs. 'No I didn't, but THANKS' :ROFLMAO:
 
Bperry said:
I’d really like it if the rain and snow lowered my pH over winter but mine has been crazy high when I open back up in March. Has anyone verified that the pH actually does drop down?
Click to expand...
I have a mesh cover and with the snow and rain my PH is always a little bit lower after opening. I get a reading of .2 to .4 lower than at closing.
 
  • Like
Reactions: Newdude
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply