To increase the acidity, use Citric Acid If you want to increase the alkaline use Triethanolamine 99% How to use : Try to click to read it. There are detailed instructions for use. The device you should have is กระดาษลิตมัส or machine วัดค่า pH Thank you.
If doing it for the first time, it will be used to adjust the ph value in the formula. It must be put in the last step. to gradually adjust the ph value as we want. Thank you.