pH Calibration Buffer 2-Pack, 500 mL (1.06 Pint) Each: pH 4.00 and pH 7.00; NIST Traceable Reference Standards for All pH Meters

Great product worth it

Price was right. Works to balance my spa for correct pH range

I would recommend this product

Will be a future customer for sure!! This solution is very Accurate, have compared it to other solutions and there is no comparison if you are looking for accurate solution to calibrate your Ph meter.. FYI..if you are using a Bluelab PH pen made in the last year or 2...Throw it away and do not trust it!! Lots and lots of people complaining about inaccurate readings and the pH Pens going bad and will not calibrate...Then bluelab not standing behind their products or their warranty!!

Products made August and October 2018 with expiration dates of August and October 2020! I own and operate a small cheese plant so don't use a lot of product. Nice to know it won't expire before I use it up. Rapid delivery as well.

The pH meter and the test results are useless without checking and calibrating your meter.

I have used testing calibration solutions like this for many years and these products are a great value for the money. Plus, they come with certifications traceable to NIST!

The 4.0 ph bottle was a quarter empty and the 7.0 ph bottle was half empty. I'm missing a combined 3/4 of a bottle between the two. That's a lot of liquid to be missing for 20 something dollars. The issue is the white safety tabs under the caps, they aren't very good and the caps aren't put on very tight so they leak. Luckily the bottles were put in a bag so the liquid didn't leak all over the place. Regardless the liquid does its job and I'll likely buy more if I can get the leaking bottle situation figured out with them.