Water Testing (Ph) Question

[walleye]

I have a Taylor 2106 kit, I went to do a routine test on my tub a few minutes ago, got the following results:

Bomine = 3.5 ppm

TA = 35

CH = 250

PH = off the chart low. Took 10 drops of reagent to get it back up to 7.4. I panicked and started to read on how much of what to add. I tested twice with same results. I decided to go get a fresh sample right out of the tub, and it reads 7.4. (big relief here) I always keep a close eye on things, usually daily if I am at home. Question is this, I took a glass Pyrex measuring cup and used for all tests. I did the PH last. Could the water sitting there and cooling caused this? It might have been 7-8 minutes.

[waterbear]

I suspect that the glass cup was not clean and contaminated with something acidic Repeat the TA and pH tests and see if they read the same since a TA of 35 also indicated acidic water

[walleye]

I think your right Waterbear. I did retest last night, and the PH was decent but the TA remained low. I added a ounce of Baking Soda, tonight the PH is 7.8 and TA is 65ish. I did buy the floater you and Chem Geek recommended, and I am working on the setting. The instructions suggested 4.5 on the scale, but that keeps my bromine at around 10 PPM, I dropped to 1.5 and it went down to 5 ppm so I upped it to 3.5 thinking it was coming down, but tonight back to 10 PPM. I am now setting it to 2.5 and we will see. Once I zero it in that thing is going to be great. (my tub is about 400 gallons) THX for all the help.