About to throw in the white towel

[PoonTang]

Honestly I wouldnt worry about it. I know that the majority of the people here never even test for it. If your tank is not showing any problems then leave it be. You need to be concerned with the amount of variation more than the actual number itself. If your going to use the Kalk then only use it at night it will keep your from dropping too low and then in the daytime your lighting will take over.