Are you dripping the kalk in slowly, and at night? If not, that could be the root of your problem. If you're adding it too quickly and during the photoperiod, that can eat up your alkalinity.
Randy, sorry if I offended you, I realize you have a lot of experience and your help is greatly appreciated. Your whole response revolved around some missinformation though, which was my fault, I admitt that. But, if you had read the rest of the thread though, your response would probably have been different.
So I just made up water to do a water change, and for fun I tested the Alkylinity. It was only 0.7 milliequivalents. I use red sea salt and RO water. Is that what it should be? I thought freshly made up water was supposed to be a bit higher in alkylinity? Oh, and the test kit I have is also red sea. I think I need a Salifert kit....
