(04/17/2013) - The refill kit is not the same as the Pro test kit. The original liquid would turn from blue to red at the KH level. This matched the instructions on the card. The replacement kit turns from blue to yellow, which is much harder to see. Needless to say I was shocked that there was a difference and apparently no explanation. Google search for 'red sea pro KH test refill color yellow' shows many are having this issue.