Your KH went from 7 to 9? At any rate, the chart and calculator I reffered you to is the same one thats on Chuck Gadds page, he was kind enough to allow me to use it. As long as you are in the 20 to 30ppm range, you are fine... Chuck actually recommends a little lower.
The only thing you need to be careful of is not to drop your pH to fast, or your fish may go into shock.
King admin www.aquabotanic.com