Besides Alk & Ca, need to make sure phosphates and magnesium are within acceptable prams for good coralline growth.
Are you using RO/DI for make-up & water change water& have you tested the output quality?
All my "show" pieces are from frags I've acquired trading within our club, in fact many are frags of frags that I've given out over the years.
Happy reefing!
Glenn R
As P.T. Barnum used to say "There's a Sucker Born Every Minute"
Or it's just some folks have more money then sense.
All said, I'd pay a good amount for a nice sized piece, but you wont see me on a 5 year long waiting list!
Sounds totally normal for a healthy Trachyphyllia (open brain).
The skeleton is the base, and should be firmly planted in the sand.
Happy Reefing
Glenn R
Only the water evaporates, all the salts, minerals etc stay behind.
Your corals and the fish waste will consume minerals, that is replaced with water changes and supplements. (kalk, Ca reactor, 2 part...)
HTH
Glenn R