I'm a new practitioner of BBB and am using the Taylor K-1000 and K-2006 test kits.
I'm keeping the pool guy for awhile since I can't commit to maintaining the pool full time (work, travel, etc.). It's handy to have him around to vacuum, brush, clean the filter and so on.
A major sticking point has come up over pH. The pool guy and I agree that a good number would be 7.2. He would also accept 7.5. He "tests" pH by flicking a drop of reagent into the pool and reading the color. This is what he's always done and he generally adds acid after the test, as if the pH was too high. Now that I have Taylor test kits, I am able to "shadow" what he is doing.
Here is what has happened:
Pool Guy: "pH should be 7.2"
Me: "I agree"
Pool guy does his reagent-drop-in-the-pool pH test, pours in acid, then leaves
I test pool (several hours later), and pH reads as yellowish, which is off the chart.
I add borax and get pH reading to 6.8
I add more borax and get pH to 7.2
I add baking soda (to increase TA) which gets pH to 7.5
Pool Guy: "pH is WAY too high." (This said after he flicks drop of reagent in water and it's INDIGO for the first time. Prior to this it's always been in the orangish/reddish range.)
Me: "I got 7.5 earlier today. Let's test it with my kit."
I read 7.5 and pool guy says it's higher. We put white paper behind the comparator and I still say 7.5 and he still says higher. He then pours acid all around the perimeter of pool.
Several hours later, I test pH at 6.8 or lower and start pouring in borax.
In the pool guy's defense, he's generally been very good about preventing algae, and he attributes that to a "correct" pH. However, we have copper piping and have experienced leaks. I've read that running a pool on the acid side is bad for metal and I'm wondering if the low pH has been preventing algae but contributing to pipe damage.
Second-guessing myself, I've tested the pH over and over again to make sure I'm not reading the colors wrong. IMO, the pH test is one of the easiest.
FC/TC is below 10 ppm so that shouldn't be affecting the pH readings.
Can anyone shed light on why a mostly competent pool guy is making my pool acid, while "talking the talk" of 7.2 - 7.5 being the correct range? What re-agents might he be using and why is he doing single drops in the pool?
pH: 6.8 or lower after pool guy pours in acid (was 7.5)