Confused about pH

angela9298

New member
Apr 16, 2025
4
Atlanta, GA
Hi Everyone, I'm a new pool owner. We bought a house with an old in ground vinyl pool last year, and it needed rehabbed. We got it remodeled, new liner and coping, and I'm now in the process of getting it up and running. Working through some piping/ equipment issues, but my question right now is about the water.

So we filled it with the hose, and it had been sitting about a week before I tested the water. I have a Taylor test kit and these were the values on my first reading. pH - 7.9, TA - 40 ppm, CH - 50 ppm. I had not added anything to the pool yet. For the pH, I did the acid demand and the water immediately turned yellow with one drop, so the pH dropped to about 7.1. It surprised me, but I thought maybe because the TA was low and there was no stabilizer.

After that, there were some cheap test strips left with the house, and I decided to try it just to see if it aligned. I was surprised to see the pH was reading low, like 7.0, but they had expired. I bought a new set just to try it again, and low and behold the pH was reading the same on the new strips.

I believe I read that high chlorine can cause false pH readings, but there is no chlorine in the pool yet. Any ideas on what the issue might be? Thanks in advance!
 
Hi Everyone, I'm a new pool owner. We bought a house with an old in ground vinyl pool last year, and it needed rehabbed. We got it remodeled, new liner and coping, and I'm now in the process of getting it up and running. Working through some piping/ equipment issues, but my question right now is about the water.

So we filled it with the hose, and it had been sitting about a week before I tested the water. I have a Taylor test kit and these were the values on my first reading. pH - 7.9, TA - 40 ppm, CH - 50 ppm. I had not added anything to the pool yet. For the pH, I did the acid demand and the water immediately turned yellow with one drop, so the pH dropped to about 7.1. It surprised me, but I thought maybe because the TA was low and there was no stabilizer.

After that, there were some cheap test strips left with the house, and I decided to try it just to see if it aligned. I was surprised to see the pH was reading low, like 7.0, but they had expired. I bought a new set just to try it again, and low and behold the pH was reading the same on the new strips.

I believe I read that high chlorine can cause false pH readings, but there is no chlorine in the pool yet. Any ideas on what the issue might be? Thanks in advance!
Post a picture of your Taylor pH test. Some newer folks can have a hard time with it at first. It’s the hue of the color that matters, not the intensity of it. The Taylor kit also measures 7.8 or 8.2 so not sure how 7.9 was achieved.
 
Post a picture of your Taylor pH test. Some newer folks can have a hard time with it at first. It’s the hue of the color that matters, not the intensity of it. The Taylor kit also measures 7.8 or 8.2 so not sure how 7.9 was achieved.
I'll have to redo the test to take a picture, but it was pretty simple. I did do it twice as well. 5 drops of reagent, holding the bottle vertically, then inverted to mix. It was in between the two values which were 7.8 and 8.0 (not 8.2), hence the 7.9.