VIVOSUN 18-Pack pH Meter Buffer Solution Powder, pH 6.86/4.00/9.18, pH Buffer Powder for Precise and Easy pH Tester Calibration

Worked very well. Ph level was perfect compared to another brand I used. Pretty good value. It’s super accurate. The brand is one that I trust and have always. I only had to do it twice just to make sure and it came out perfect both times.

An essential aid , tool in growing quality plants and a good value . The product performs very well and gives you accurate readings . Easy to use and store for use a long lasting product

They work but the crystals take forever to dissolve.

I love all the Vivosun products I have. This is a nice little kit to keep my Vivosun PH pen calibrated.

I have 2 pH pen. I haven't used them in a long time, so to get an accurate reading I needed to calibrate them. This product worked perfectly.

Perfect and easy to program I need more

Make sure you use the exact amount of water for each packet. Make sure you can convert their temperature chart and how far the reading will be off. I tried multiple times with these packets with no luck. One solution would be close but the other 2 not so much.

works great