just a note: most KH test kits give results in "mg/L" - that is the same as ppm.
Yeah I was wondering the same thing. This has been very confusing to me. My test kit also give results in "mg/L" and I don't know how to measure that in ppm. For example my test kit says to add one drop of solution at a time until it turns a certain color and take the number of solution drops added and multiply it by 20 for GH and 10 for KH. My tests resulted in 11 drops of GH solution and 11 drops of KH solution, which I then multiplied.
The chart only goes to 15 KH Can someone please explain this to me? Thanks.