This video shows how to take some 20% Hydrochloric Acid (aka HCL or muratic acid) and bring it down to a 4% level with distilled water. I also go through some of the math used to figure the quantities of water and acid to mix. Safety is very imporrtant whan working with such chemicals like this so be careful if you try this. Use hand and eye protection. The 4% HCL can be mixed with sodium chlorite (about 22.4% or sometimes higher) to make Chlorine Dioxide "MMS". The HCL can be purchased at a hardware store for about $10-15. When making Chlorine Dioxide, I call this mix the "A" mix. A is for "Acid" and "Activator".

Spreadsheet is at:
https://docs.google.com/spreadsheets/d/1v5thZf3FTXQ3lA8jN1NOMOEa0Ns7ETfPVR8IiPGo7i4/edit?usp=sharing

When in the spreadsheet, go to the "file" tab on the top left and "make a copy" and it will put a copy on your gmail google drive account. If you want to have this in excel, go to "file" and "download as" an excel file.