The base tissue growth will be referred to as encrustation growth. A Porites cylindrica propagation after eleven weeks. Before we can begin propagating corals it is necessary to have a good foundation for coral growth. This means an establish reef tank with stable parameters and a history of successful, and preferably rapid, coral growth. It will not be possible to propagate stony corals if the hosts themselves can not grow well.
Most experienced hobbyist know the general requirements for a well run reef aquarium.
There are two though that I feel I need to empathize for coral propagation. The first is lighting. I have found that the frags seem to need at least as much if not more light than the host to insure good recovery and early growth rates. So it may be necessary to put the grow-out frags nearer the light source or even add additional actinic light for faster growth. This is particularly true of Acropora spp. which will need a great deal of light energy to rapidly encrust at the base.