Atlas Scientific pH 4.00, 7.00, & 10.00 Calibration Solution 125ml - 4oz (Pack of 3)

Works as expected. Good value and easy to use. Makes calibration very easy to do. I wouldn't reccomend if you need to calibrate often as you may go through it quickly. Perfect for the hobby "calibrater". Lol

If you have a pH meter, you MUST have calibration solutions. Most of the things I measure are in the pH 4 range and the pH 7-8 range. So this package of 4 and 7 is perfect for me. If you measure things much higher than 8 you may want to consider a bottle of 10.Pools should be in the 7 range, so 7 is perfect. Acidified foods are in the 4 range, so 4 is perfect. Salt water aquariums are in the 8-8.3 range so 7 or 10 would work.Remember to throw away used Buffer and not to pour it back into the bottle. You only need a small amount so it is pretty cheap to use.

Tuve un inconveniente porque mi pedido se perdió pero amazon volvió a enviarlo y llegó perfecto

I calibrated my PH meter on a 15 min break Quick and ez Lust the way I like em

The product is just as described. I have no problems with the company that sells this, HOWEVER, I do have a real problem with Amazon delivery. Until about a month ago, my orders were delivered with my USPS mail, but the past 2 orders I have placed were NEVER delivered on time, it was always a day or even 2 days late.

For a spa or pool, I don't think you need the 4.0 and 10.0 unless your pH meter calibrates on a three-point curve. Usually for a pool or spa, you only need the 7.0

I hear its very important to calibrate meters for a sanity check and this gets the job done, good price of all 3. my watermelons and tomoatos are thanking me for finding a faulty meter

Used to calibrate my pool ph meter.