Various Testing Results - Which to Follow?

[pflaherty3]

These questions could probably be added to my post related to my Baquacil conversion http://www.troublefreepool.com/threads/76443-Baquacil-Conversion-(Starting-5-31)?p=661169#post661169 but I thought I would try here first. My other thread has been stale because my conversion got held up do to some leaking pipes and pump.

I want to get my pH to 7.2 before I start the conversion. I've read that is the ideal number so chlorine works the best. However, I am not sure what my pH level really is.

Results for today (6/8):
Pool Store
- The pool store uses a test strip, and then a machine tests the levels and prints out the results and recommendations based on those results.
- pH: 7.0
- TA: 90
- Biguanides: 48

Baquacil Test Strip
- pH: ~7.0
- TA: ~80-100
- Biguanides: ~50

Taylor Test Kit (from TF100)
- pH: ~7.8
- TA: 90

The results above were similar for pH testing done on 6/6 as well. TA was lower on 6/6, so I added 64 oz of baking soda, and now it is up to 90 on all tests.

I also tested my tap water (city water) with both the Baquacil test strip and Taylor Kit just to see what results I would get.

Baquacil Test Strip (tap water)
- pH: ~7.0
- TA: ~50

Taylor Test Kit (tap water)
- pH: ~7.8+
- TA: 50

So, what should I do next? I realize the Taylor Test Kit is a preferred kit as part of the TF100; however, I am still nervous with pH test results so different. One test would indicate I should increase pH and the other that I should decrease pH. I believe I am following all of the testing procedures properly.

The big question is, should I be adding some muriatic acid now, or should I just start the Baquacil conversion???

 

[woodyp]

Use the Taylor results. Only add enough MA to drop your PH HALFWAY to where you want if to be and recheck your results in an hour.

 

[Richard320]

If the FC is above 10, it will react with the Taylor reagent and make pH read falsely high.
If you post all the test results, it helps.

 

[pflaherty3]

I just added some MA per your instructions and Pool Math and will recheck in an hour.

I do not have any FC at this point. I have not started the Baquacil conversion yet. That is why I didn't post any other information; I didn't think they were applicable yet.

 

[Richard320]

I just added some MA per your instructions and Pool Math and will recheck in an hour.

I do not have any FC at this point. I have not started the Baquacil conversion yet. That is why I didn't post any other information; I didn't think they were applicable yet.

You're right -- they aren't. I thought you were in the midst of it.

 

[Patrick_B]

Use the Taylor results. Only add enough MA to drop your PH HALFWAY to where you want if to be and recheck your results in an hour.

X2 on the testing, and X10 on the under dosing for a pH change. It is ALWAYS a good idea to put in a little less acid than you need to reduce pH. You can always add more if you need it. Doing the opposite can get you in a lot of trouble.

 

[aussieta]

how old are you testing reagents?
have they been stored correctly?

 

[pflaherty3]

Brand new -- I just purchased the reagents (TF100 XL Kit) at the end of May. They have been stored inside and aren't exposed to light unless I am conducting tests.