DuvinDD 20 Pack pH Calibration Solution Packets 6.86/4.01 for Accurate and Easy Calibration of pH Meter, pH Standard Buffer Powder Solution

I like using these powdered calibration packets, they are simple and straight to the point. You don't have to throw them out after 30, 60 or 90 days like the liquid calibration solutions tell you to. All you do is pour each packet into a cup with 250ml of distilled water, make sure its dissolved, insert the pH pen and hit calibrate. BOOM! Calibrated. Easy peezy, lemon squeezy! Highly recommend these packets.

This pH calibration solution works as expected. Shipping was fast. The powders dissolve easily and I was able to calibrate my pH meter without any issues.The seller is also worth mentioning. They were helpful and responsive when I had a question. Good customer service is always a plus.Overall, a solid product and a good buying experience. I would definitely recommend.

This is a nice set to help keep my ph meters calibrated. Would buy again.

Using a powder buffer solution is more tedious and annoying than a premixed solution, but this does a great job. The only issues I had was when the water temp was too cold for the powder to dissolve properly.

Amazon site helpful about which set of solutions needed for ph unit.

The team was very adamant about ensuring that my pH monitor was satisfactorily calibrated... while the first few powders they sent did not dissolve properly and appeared to not calibrate correctly, they proactively reached out to verify it was working (without me even issuing a complaint) and sent replacement powders for free. The first set of replacements did not work, so they sent a second set of replacements, which worked well and calibrated my pH monitor as expected.

Product is exactly as it is described to be. I actually took small water bottles, mixed a solution in each one and used those 3 bottles to calibrate my PH meter for over 5 months ths without the bottles dropping or rasing in PH.

Works great keeping my pH meter in check

works good

Kit ph

These are always accurate and you can store the solution in a cool dark place for months on end. At roughly 75 cents a pack to make 250ml its cost about $3 to make a litre which cost $14.99 at the hydroponic store. So you save $12 mixing your own.

Works as it should

Cheapest option ive found so far, accurate and very easy to use. Don't waste it. You can store the solution for couple weeks.