15-Pack pH Meter Buffer Solution Powder, Easy and Accurate, Make pH Calibration Solution 4.01, 6.86, and 9.18

Prompt delivery. Great value. My only negative is that it would be helpful if there were more information about using the buffers; specifically, whether all three should be used every time the meter is calibrated. Or is it sufficient to use only the one that is closest to the test sample? I wish I knew. Either way, the fifteen buffer packs are generally good for only five calibrations. But that's still good value.

Very cost effective and takes up very little space. pH variation with temperature is printed on the sachet. Prior to this I'd bought bottles of pre-mixed buffer. Not any more. It's probably obvious to most people, but do check that these buffers are the right ones for your pH meter. One minor quibble: the red packet says "pH 4.01@ 25 C" on the front, but the table on the back says 4.00 @ 25 C. Anyone who needs that level of accuracy won't be using this product, but it's annoying.

You know when I was looking for ph buffer I didn't know which one to get I had to do my homework and read reviews and specs but I'm glad I chose this one because it actually does what it says and it is very accurate I highly recommend this.

Used these to calibrate my ph probe for my aquarium, enough packets to calibrate for a good while

Very simple to use and accurate. These were very easy to use. It is always good to be sure your ph meter is set correctly!

These are great calibration solutions if your meters need to be calibrated with these levels. You dissolve each package into 250mL of distilled or deionized water. They should last me a while.

It’s ok, it does what it’s supposed to but the only thing I don’t like is some of the packs take a while to dissolve. Other than that they work.

Easy to use and seems to work