I got the test completed but the instructions are poor I don't understand them.

I tested my KH (had to add 5 drops to 5ml of tank water to turn yellow)
I tested my GH (had to add 9 drops to 5ml of tank water to turn light green)

What do these numbers mean. There's a chart wight the instructions but it's extremely confusing. The only reason I wanted to check the water is because I'm switching to ro di water tomorrow and don't want my discus to die because of huge changes in water parameters.