Tried a six month experiment.
I dose calcium chloride and sodium carbonate to control calcium and alkalinity. I also occasionally add magnesium when it tests low. At the same time I also dripped Lime water (Kalkwasser) at night. I got to thinking that the Lime Water was redundant and decided to stop it for a while and take some pictures of my hard corals before and after. I run a 500 gallon system, so I have elected to supplement than big water exchanges. I only exchange 5% every two weeks.
The pictures are crummy, so I'm not posting them, BUT the results were interesting.
Water parameters were kept the same by upping the dosers to make up the difference from stopping the Lime Water. Most corals showed no visible change, but all my chalice corals stopped growing. They even started to die back. My Acros also slowed down without the type of calcium from the Lime Water. Just proved to me that there are many different ions of calcium and some corals like the calcium delivered by Lime Water rather than calcium chloride. For the new folks, the Part A and Part B solutions sold for controlling calcium and alkalinity, are composed of the two chemicals mentioned above.
Something else that was weird was the zoas seemed to like the Lime Water too.