Power pool cover and Alkalinity and Ph

[mlulm]

I just found this site and wondered if anyone knows anything about power pool covers raising ph.
My pool store is telling me that not opening my pool cover enough, is causing my ph to go up.
If this is true, is there a way to avoid this problem?
Thanks

 

[JasonLion]

It is usually the other way around, putting on a cover can often help slow the rate of PH increases.

If you post a full set of water test numbers we can probably figure out what is going on.

 

[Guest]

my bet is high TA

 

[mlulm]

My ta was around 330 or above, when my ph went up. I lowered my ta to what looks to me, using drops and also a test strip, to about 240. Yesterday I had the pool store test a sample, they use a strip and a machine, they said my ta was now (92 - adj 60) and that this could cause equipment corrosion, sufface damage, and cause swimmers discomfort. They recommend adj ta of 125-150.

 

[Poolidiot]

To be able to give you the correct help you need, you need to post a FULL set of numbers:
FC
CC
TC
PH
TA
CYA

And what type of pool you have, how many gallons ETC.

 

[mlulm]

Here they are

FC 4
TC 4
PH 7.5
TA 220
CYA 100

My pool is 16X32 inground vinyl with about 17000 gals.
Since the problem with the ph I have added 3 gals of muriatic acid, half a gal at a time, while adjusting the ph.

 

[JasonLion]

Your TA is very high. That is going to cause the PH to constantly drift up. You should lower your TA level, there are directions on doing that here.

Your CYA level is also very high.

 

[mlulm]

I'm just worried about the difference in the ta tests I do vs the pool stores.

 

[frustratedpoolmom]

My ta was around 330 or above, when my ph went up. I lowered my ta to what looks to me, using drops and also a test strip, to about 240. Yesterday I had the pool store test a sample, they use a strip and a machine, they said my ta was now (92 - adj 60) and that this could cause equipment corrosion, sufface damage, and cause swimmers discomfort. They recommend adj ta of 125-150.

Hi there! Don't you love pool stores?

Even if their test is accurate, and I trust my own testing over theirs any day.... a TA of 92 is not going to cause equipment corrosion or anything else, there are several things that come into play chemistry wise for that to happen but a TA of 90 isn't going to do it...A TA of 90 is perfectly fine. And actually, there are lots of members on here that have TA lower then that in order to prevent PH rise. I'm surprised they recommend a TA of 150, I think that's high.

What kind of test kit are you using, you mentioned drops and strips. I'm curious of the type of drop kit you have?

 

[JasonLion]

Test strips, including test strips read by an electronic reader, are amazingly unreliable. Drop test results are much better.

 

[mlulm]

I used
1. bioguard drops which showed around 230
2. auquachek 7 was between 180 and 240
3. walmarts kit which was easiest to read showed 220

I'm going to order a good kit.

 

[Guest]

My ta was around 330 or above, when my ph went up. I lowered my ta to what looks to me, using drops and also a test strip, to about 240. Yesterday I had the pool store test a sample, they use a strip and a machine, they said my ta was now (92 - adj 60) and that this could cause equipment corrosion, sufface damage, and cause swimmers discomfort. They recommend adj ta of 125-150.

Where you put the TA depends on whether you are using an acidic sanitation source (stabilized chlorine or a bromine systen and/ or MPS for shocking) or not. Many pool store employees and even maintenace techs and pool builders do NOT understand this very simple bit of pool chemistry which is taught in every CPO (commercial pool operators ) course and even a lot of CPOs fail to grasp this simple concept. If you are using bleach you want your TA at about 70-80 ppm. If you are using trichlor you ant it about 100-120 ppm. Low TA has no impact on equipment corrosion. The danger of corrosion comes from low pH which can happen when using trichor or other acidic sanitation sources and not monitoring TA (and pH). The TA gets 'used up' and the pH 'crashes'.

 

[mlulm]

I'm just now changing to the BBB system. I was using a lithium chlorine from the pool store.
thanks

 

[Guest]

I'm just now changing to the BBB system. I was using a lithium chlorine from the pool store.
thanks

Lithium hypochlorite is a very expen$ive unstabilized chlorine. Other than the price it is an excellent choice. It also requires a low TA like bleach for pH stability.

 

[mlulm]

I was wrong I was using a stabilized chlorine. The Lithium hypochlorite was for shocking.

So what I got from this is.
The pool stores ta test isn't accuate.
The reason my ph went up when I left my pool cover on was because my ta was above 300, not due to the cover.
Thanks

 

[mlulm]

Do you know of any guildlines for how often and long you should have your pool cover open.
I'm interested in this because of vacations.
Thanks

 

[frustratedpoolmom]

Do you know of any guildlines for how often and long you should have your pool cover open.
I'm interested in this because of vacations.
Thanks

I've left my cover on for 11 days with no problems, shocked before I left and had a friend add a jug of bleach while I was gone, mid week.

 

[Butterfly]

Do you know of any guildlines for how often and long you should have your pool cover open.
I'm interested in this because of vacations.
Thanks

Hi mlulm,

If you do a site search for +cover +breathe you will find several threads. Here's one: solar-cover-on-all-the-time-t4204.html?hilit=%20cover%20breathe

hth :-D