update:
The calvus is doing well, swimming a bit and hiding behind one of the rocks piles. The others are all doing well, too. How soon should I expect problems to arise if there is more than 1 male shelly?
Thanks!
Glad the calvus is up and about - lovely fish - probably just a little bit of acclimitisation stress.
I think you'll find that when a pair forms they (the shellies) will beat the tar out of any other competitor for a breeding site. Pair forming - I don't know I'm afraid. Very quickly with the right set up but also could be in a few weeks or after some months subject to the environment in the tank.
Would love to see pics of it - sounds really great.