ph Question

[pink]

I came here back in May and my pool has been doing great ever since refilling and Slamming. I had a question about PH though. It seems to rise rather quickly. Is this due to simply dumping liquid chlorine in the pool?

For example I measured my Ph on 6/28 in the morning and it was more purple than the scale on the Taylor test would allow. So I think it was 8.2. I added 2 quarts of MA and read the ph later that evening and it was at 7.4. The weather has been mostly cloudy in the morning with temps in the high 70s in the late afternoon. Filling the pool with 1qt of 12.5% Chlorine every night seems to keep the FC levels between 2.5-5.

I checked the pH yesterday 5 days later on 7/3 and it's already above 8.0 on the color match, so like 8.1-8.3. Is this just normal? I typically just add one quart of MA a week and the ph drops to about 7.8. But it looks like it doesn't hold on there very long if I noticed a 7.4 to 8.0+ in 5 days.

The day the ph reading was at 7.4 the TA was 120.

 

[setsailsoon]

Pink,

Welcome to TFP!

Addition of chlorine causes an initial pH rise but as the chlorine reacts that affect is neutralized. So net impact to pH is zero.

For almost all pools pH gradually rises due to aeration from the surface and any features like a spa spillover. Lowering your TA will help to stabilize pH. Try dropping it to 80. Many of us run even lower.

Chris

 

[ajw22]

pH rising 0.1 per day is not unusual with a TA over 100.

As Chris said, lower your TA to 60-70 over time. The lower the TA the slower the pH rise.

What is the pH and TA of your fill water?

 

[Richard320]

With 120 TA, what you describe sounds completely normal.

Each time you lower pH, you'll lower TA a little, As TA goes down, the amount of acid you need to add to effect the pH change will go down, and the intervals between adjustments will lengthen. That's the beauty of doing your own testing. You'll learn the patterns and be able to make corrections quickly and efficiently.

 

[pink]

pH rising 0.1 per day is not unusual with a TA over 100.

As Chris said, lower your TA to 60-70 over time. The lower the TA the slower the pH rise.

What is the pH and TA of your fill water?

Fill water ph is 8.3 and TA is 170.

I'll keep at and see how the TA goes. After initial slamming TA was around 150 in May, then 140 in June and as most recently120. I'll keep at it, thanks for the confirmation that everything is as expected.

 

[setsailsoon]

How To
Lower Total Alkalinity

 

[pink]

Also, I have a question about testing the TA. Do you stop adding drops when the solution turns to a dark brownish color or on the next drop which turns it an obvious red?

For example, at 10 drops the mixture slightly goes red but then quickly goes back to green. After 11 drops I swirl, it turns red for a second now but then the mixture tries to go back to green but stays like a dark brown instead. 12th drop swirl and it stays red. Do you stop at the dark brown or the obvious red?

 

[Richard320]

Also, I have a question about testing the TA. Do you stop adding drops when the solution turns to a dark brownish color or on the next drop which turns it an obvious red?

For example, at 10 drops the mixture slightly goes red but then quickly goes back to green. After 11 drops I swirl, it turns red for a second now but then the mixture tries to go back to green but stays like a dark brown instead. 12th drop swirl and it stays red. Do you stop at the dark brown or the obvious red?

You go beyond red until it gets no redder. Or pinker. It looks like Barbie pink to me. For you 12 turns it red. Probably 13 will turn it redder. 14 probably does nothing, so you deduct it, which makes TA 130.