Using Liquid Chlorine and pH

[Nicki1016]

Ok, I have a general question which I hope you can help me with. I have been using liquid chlorine 12.5% in my pool. As expected, the pH rises. pH is reading at about 7.8 before adding chlorine and rises to about 8.0 after addition of chlorine. My question is should I adjust the pH at this time with muriatic acid or should I wait, and if so how long, to make the adjustment. I understand the pH increase is temporary and will decrease as the chlorine is used up. Also, is it okay for the pH to be at 8.0 temporarily? I have been adjusting after a couple of hours and by next morning it is alittle lower than I would like. Todays readings:
pH 7.8
FAC 7
CYA 60
TA 60
CH 230

 

[jblizzle]

It is fine to have that pH at 8. Especially when your TA and CH are lower like yours. Check out the CSI.

Don't worry about the temporary pH rise.

 

[Nicki1016]

Merged threads. TFP Mod.
I am wondering if what I am doing is right. Everyday I am adding around 4 cups liquid chlorine to raise the level to around 6.5. The pH initally reads at 7.75. After 3 hours, the pH is only at 7.9 and never goes back to the original reading. I am adding around 4.5 oz acid daily to bring it back down to 7.75. I understand that the rise in pH is only temporary until the chlorine is used up. My questions are: Why is it not returning back to pH 7.75 without the addition of acid on a daily basis? Also, is it okay to be adding acid daily? I have been checking my TA every 5 days and it stays steady at 60.
Todays readings before any additions:
FAC = 4.5
pH = 7.75
Temp 83 degrees F
CYA = 50
TA = 60
CH - 240
After adding 4 cups liquid chlorine 12.5%
FAC = 6.5
pH = 8.
Could all of this be due to keeping a lower TA? Isn't a lower TA better than a higher TA?

 

[mknauss]

As Jason said, only lower pH when it reaches 8 when you test. Do not test pH right after adding liquid chlorine.

 

[Nicki1016]

Reposting this thread. I am adding 4 cups of 12.5% iquid chlorine daily. Th pH , I feel is rising too much, from 7.75 to 8.0 and never returns back to 7.75 or even close. It drops back to around 7.9 three hous later and never lower. I adjust daily by adding 4.5 oz muriatic acid daily to bring back down to pH 7.75 TA is staying at 60 with this process. Is this due to my TA being at 60? What is going on. The rise in pH is too much and doesnt appear to be temporary.
Readings before adding chlorine:
pH 7.75
FAC 4.5
TA 60
CYA 50
CH 240
Temp 82 degrees F
After adding 4 cups liquid chlorine: According to Pool math, my FAC should be 4.5 min. and target 5-7
FAC 6.5
pH 8.0

 

[Nicki1016]

As Jason said, only lower pH when it reaches 8 when you test. Do not test pH right after adding liquid chlorine.

It is going way beyond 8.0 if I do not add acid daily because the next day I will be adding additonal chlorine. But at this temp 82 degrees, it is pretty close to scaling and the temperature rise to around 88-90 degrees quickly.

 

[mknauss]

The chlorine does not raise your pH day to day. That is most likely your fill water. What is the pH and TA of your fill water.

 

[ajw22]

What are you measuring your pH with that you can say it is 7.75?

 

[Nicki1016]

What are you measuring your pH with that you can say it is 7.75?
[/

I am using Taylor K-2006 kit. All reagents are good. I will check the pH, chlorine, and TA of my fill water and get back to you.

 

[ajw22]

I think you are giving a precision and repeatability to the pH drop test that doesn’t exist.

 

[Nicki1016]

Sorry, but I don't understand your reply. Can you elaborate.

 

[jblizzle]

He is saying that you can't possibly read 7.75 on the color matching pH test.

 

[tim5055]

How old is your pool?

Do you have a spill over spa, water fall or other water feature?

pH naturally rises in most pools, but it rises faster with new curing plaster (figure a year to 18 months) and pools with active water features.

 

[RMcGirr83]

^ what Tim said.

Our pool was finished in November and I used to have to bring the ph down daily....now it's roughly every two days. Just wait for it to get to 8.0, add enough acid to get to 7.6....repeat.