Confused about how to use Atlas pH calibration solution

[Greenpassion]

Hi all. I have been using Vantakool pH tester, and Atlas scientific pH calibration Solutions. Each small bottle of the pH 4.00, and the pH 7.00 is 125 Mill. So what I have been doing, is taking 2 small clean jars with wide enough mouths for me to use my pH tester. I calibrate at the 4.0, rinse it and calibrate at the 7.0. So far it has been doing pretty well. But now I can't seem to calibrate in the higher range. Was I supposed to be throwing this calibration solution out after I used it? I can find no instructions anywhere. I wasn't even sure if it was supposed to be diluted with water so I had to ask the company. Are these only single-use bottles of calibration solution? Does anybody use this? I really have no idea what I'm doing. Can anyone suggest a good calibration solution? And with my vantakool pH tester, it does not need to be kept in a storage solution. Does anyone use the vantakool pH tester?

[Flockshot]

I use a Blue Lab, so I can only speak to that one. The PH solution is ok till it becomes contaminated. Mostly by having some 7.0 on the meter when it goes into the 4.0 and visa versa, and the clean water rinse you are doing is probably in about PH 7 water.

I use fresh solution at the start of a grow, and at beginning of flower. I keep it sealed otherwise.

A good check, is on your own tap water. With a calibrated pen, test your tap water several times over a couple days. If it is a consistent PH, then your tap water can be used to test the accuracy of your pen between calibrations.

I use General Hydroponics solution.

[Greenpassion]

I probably should have mentioned that I won't use chemical pH Solutions because I am growing in Kindsoil. I use the natural organic Earth Juice crystals. But that is not the issue. My problem is with the solutions that calibrates the ph meter...

[Flockshot]

You are calibrating your meter, not putting it on your plants.
Are you looking for an organic solution for calibration? I have never heard of that.

[starramus]

Distilled water is pH 7 or should be. That is all I use for calibration. Cheap at under a buck a gallon from the friendly Waltons. I will double check my meter readings with this kit on occasion just to be sure.

https://www.amazon.com/General-Hydroponics-pH-Control-Kit/dp/B000BNKWZY/ref=sr_1_fkmr2_2?ie=UTF8&qid=1534109723&sr=8-2-fkmr2&keywords=hydro+pro+ph+test+kit

[Greenpassion]

Well, I just pH checked my distilled water and it comes out 6.5. So my meter must be off but how do I calibrate it? I think the solution is off too I'm all screwed up here.