General HydroponicsGH1552 PH 7 Calibration Solution for Gardening, 1-Quart lab-chemical-buffers, Green

Use it for single point calibration on a Ph pen. Works great, no comolaints.

I felt i needed to clarify what this product is used for, because of all the reviews stating they used this to ph their water or nutrient water. GH has a product called "ph up" and "ph down," and that's literally what they're for. This liquid product which is green in color is specifically for CALIBRATING YOUR DIGITAL PH METER!!! And also is suitable for using as electrode storage solution. You put this in your ph cap that your ph meter goes into and it helps preserve it and makes it so your meter doesn't take a thousand years finally deciding what the ph is. Do we all understand what this is for now??? Good!!! : )

In my opinion the General Hydroponics brand is rock solid. I have used a lot of their nutrients and maintenance products and always find them to be the highest quality. This product is no exception.If you care about PH, and you should, regular testing and re-calibration of your meter is essential. For me the 7.0 is perfect since I operate in the 5.5-6.5 PH range. I used to use the 4.0 as well to verify the calibration settings but over time found the 7.0 to be sufficient. I was checking my meter once a month or so and it was not often enough so I decided to get the larger bottle so I can test my meter more often. I use the small paper Dixie cups you use in the bathroom for kids and toss them afterwards as it's best to not reuse the solution. This bottle should last a long time.Definitely recommend this for checking/calibrating any PH meter that has this feature.

Bottle is a larger size then I expected. Ive used brand this for years and find it very consistent.

Loved it

I've used this product before and it was fine but the recent bottle seems to be off by 0.2. I'm guessing it was a bad batch as another user who purchased recently had the same results. Issued a return and I'll update with the results.EDIT: Replacement has the same issue unfortunately. This was verified with a second calibrated meter as well as a different reference solution. The meter calibrated in the 7.2 solution read .2 low on the 6.86 calibration solution. The properly calibrated device read 6.86 on the 6.86 solution and 7.2 on the GH 7.0 solution.I'll give it 2 stars because this product has been accurate and a good value in the past and will probably be in the future, however, learning about this potential quality control issue makes this is a non buy for me going forward.

It’s not like I just bought a diamond ring please stop this

Cheapest 7.0 solution per oz I could find on Amazon.Doubles as a storage solution if your PH meter requires being stored wet.Generally, General Hydronics products are one of the most reliable out there, from nutes, supplements, etc. Good quality and usually the best value.

Great product.. save money on a PH reader by having proper calibration solution.

Great item to calibrate your PH meter.

Good