PH Meters and calibration solutions

[dannyboy58]

Hasn't really been a recent thread on pH meters so I'll just start a new one.

My last pH meter broke over a year ago and I brewed without it for a while. Just recently purchased another Milwaukee ph55.

When I went to calibrate the new meter I figured I'd just use the solutions I had on hand which were bottled solutions from probaby two years ago. The meter liked the 7.0 solution but when I moved it to the 4.0 in the second step of calibration it kept failing.

So I opened the little packets of solutions they sent me and calibrated the meter. Then read the old bottled solutions to see what I got. The 7/0 read 7.1 but the 4.0 solution read 5.1 confirming my past suspicions that there's a limited shelf life on the solutions.

Anyone have experience with solutions that last longer or should I just buy a few of the little packets to keep around. The bottles are pretty expensive if they're not going to last.

[sneezles61]

I have 2 bottles, one of each... I haven't compared them to a fresh set... So, mine could be off... I do keep them in the fridge... I will pour them into little snit glasses for calibrating... Then dump them back into their containers..
So when I set up to calibrate, sometimes the 4.01 rejects it.. but it tries again and it seems to accept it... I rinse in-between readings on brew day.. I use bottled water for the storage solution... Sometimes, I do check the pH of the star san, it reads just below 3.0.... I suppose I could compare to distilled water after I calibrate to verify... Now I'll need to do some investigating to see whats, what... Sneezles61
EDIT: Went to Hanna meters and read their info... I am thoroughly convinced I should get some new product... Oh dear...

[dannyboy58]

Had trouble calibrating my brand new meter yesterday, Milwaukee ph55, mentioned above in the OP. I had just two weeks ago purchased new calibrating solutions from amazon.

The brand is Biopharm. https://www.amazon.com/gp/product/B01LVU1UD1/ref=ppx_yo_dt_b_asin_title_o09_s00?ie=UTF8&psc=1

Meter calibrated to the 7.01 but when I used the 4.0 is kept saying WRNG. I knew it calibrated with the small packaged solutions and had used similar ones successfully prior to getting the Biopharm solutions. The Biopharm worked last week but not yesterday.

General Hydroponics:

Amazon.com: General Hydroponics Ph 4.01 & Ph 7.0 Calibration Solution Kit, 8 oz: Garden & Outdoor

So I ordered another set of calibrating solutions from General Hydroponics which I'd used before. Got them this morning and meter calibrated the very first time. No problem. Put it in the Biopharm solutions and the 7.01 read 7.1, the 4.0 read 3.6. So in less than two weeks the Biopharm solution had degraded....not good...sending it back to amazon and just wanted to warn you guys don't buy them.

The general hyroponics solutions always worked well for me. Only reason I tried another was the old bottle of 4.0 I had was no good but it was 2-3 years old.

[sneezles61]

I received my new solutions yesterday... I need to compare.. Since I goofed off yesterday... I won't brew until next W/E... I have a hard time believing that the solution can really go bad... Sealed and refrigerated... I'll know soon enough... Sneezles61

[dannyboy58]

... I have a hard time believing that the solution can really go bad... Sealed and refrigerated... I'll know soon enough... Sneezles61

So did I until it did.