I just completed my new 400 gal build. After placing all my critters into their new home from their holding tanks in the basement, the alk levels in the new system started to quickly fall. I couldn't figure out why because it's just the same number of coral in a larger water volume. The rock in the display is all new dry rock. The old live rock from my prior tank is in the sump. I'm not presently using my calcium reactor, choosing to dose until I have a larger population of coral. This helps keep the pH up and phosphates down during the ugly phase my tank is going through. Anyway, over the course of the next week I was dosing up to 800ml of alk a day in addition to all the top off coming out of the kalk reactor. Previously the kalk reactor handled the demand all by itself. After a week of stability the alk is now climbing daily and I've had to reverse course and reduce the dosing. I'm down to 600ml and the alk is still climbing. What gives? Why the roller coaster? All the coral look fine even the few sps frags I have. Can't figure out what's going on.