Rising PH

[andrewdunne]

Is it normal for my PH to continue to rise? The pool is less than a year old and I never had a problem with the PH rising prior to converting to bleach as my source of Chlorine. The pool is approximately 22K gallons and I'm using about 1/2-3/4 of a gallon of Muratic Acid per week to keep the PH in the proper range. I've read some of the threads about dropping the Alkalinity and bringing the PH up with aeration but not sure if the rising PH is normal given my water is aerated every day when the pump runs based on spillover from the SPA. My levels are as follows:

Calcium Hardness - 230
CYA - 50
Total Alkalinity - 100
PH - 8
Free Chlorine - 6
Chloramines - 0

Thanks for any insight you can provide.

 

[mrcarcrazy]

Is it normal for my PH to continue to rise? The pool is less than a year old and I never had a problem with the PH rising prior to converting to bleach as my source of Chlorine. The pool is approximately 22K gallons and I'm using about 1/2-3/4 of a gallon of Muratic Acid per week to keep the PH in the proper range. I've read some of the threads about dropping the Alkalinity and bringing the PH up with aeration but not sure if the rising PH is normal given my water is aerated every day when the pump runs based on spillover from the SPA. My levels are as follows:

Calcium Hardness - 230
CYA - 50
Total Alkalinity - 100
PH - 8
Free Chlorine - 6
Chloramines - 0

Thanks for any insight you can provide.

The reason you never saw a pH rise before switching to liquid chlorination is the tabs and granules you were adding contained CYA, the A stands for Acid. This is a benefit of solid chlorination IMO...however it's outweighed by the negatives of solid chlorination IMHO.

Your pool is less than a year old, which means the plaster is new, and can be causing some of your pH rise as well.

Your aeration is likely playing at least some role in the pH rise. I have a ~6ft long cascade from my spa to my pool. So I feel your pain there. I adjust my valves so that as little water runs over the spillway as possible. (doing it this way ensures you don't inadvertently drain your spa.)

Your tap water may also be playing a role. Test its pH. mine is >8.2

 

[pooladdict]

That BADU jet is certainly a cause for Ph rise.

 

[easttn]

Yes it is normal for your pH to rise and your scenario seems perfectly normal. Trichlor is acid so it was causing your pH to hold fairly steady. Now that you removed the trichlor you removed your acid source hence the additions of Muriatic Acid. If you think that is too much acid then lower your TA until it holds fairly steady. Mine holds steadily at 80. A TA of 100 isnt too bad but the higher it is then the faster the pH will rise. Also as mrcarcrazy said, aeration will cause the pH to rise faster. The more aeration you have the faster the pH will rise.

http://www.troublefreepool.com/content/129-how-to-lower-lowering-total-alkalinity

Once you get your TA where you want it, your fill water could come into play if its TA is high like mine. I can put an inch of water in the pool and raise the TA by about 3. That doesnt seem like much but when its summer time and no rain (likely in your area) then you have to add an inch every few days and then it starts to add up. No problem just lower it again.

If you lower your TA to 80 then for some reason go back to Trichlor as a primary source of chlorine (Hopefully you know better) then your pH will likely start to go down. Thats why they recommend a TA of at least 100 when using trichlor.

 

[pooladdict]

How often is the Badu jet running?

 

[aussieta]

what is your target PH?

 

[andrewdunne]

Thanks for your reply. I checked the PH of the tap water and it is 7.7. I'm thinking the spillover from the spa is driving it up. I will probably try adjusting the valve and see if that helps.

- - - Updated - - -

Not very often now that the temps are considerably lower. In the winter I just running it before testing the water and to mix the chemicals.

 

[Patrick_B]

Your TA is high enough that the rise is going to remain until it comes down some. This also happens primarily from aeration which helps the outgassing of Co2...raising your pH. As the pool ages, and the TA is worked down, the rise will tend to decrease.

Certainly, cutting down on aeration will help some. Bleach adds to pH rise, but only temporarily. As Mr. CC said, the pucks you used previously are acidic, so they helped to keep down the pH.

Your fill water pH/TA will ALWAYS come into play, so keep that in mind. We have very high TA and high pH here, so it's an ongoing fight.