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. The second requirement for stony coral growth is good water flow. I prefer a pulsed or wave action if possible and this can be done by use of a wavemaker or surge system. I have found that attached cuttings grow better with this type of water motion as it is more efficient at removing waste products and stimulating the important base encrustation process.
Propagation also requires a healthy, growing, host colony.
This is important because we can not expect the cuttings from a host in ill-health to do well. I recommend that a newly acquired first generation host be acclimated for at least several months before any attempt is made to make cuttings from it. Even then, the coral should show signs of either encrusting or branching growth and the polyps should show signs of extension. I would recommend that you wait until you notice polyp division occurring. This is a sign of good growth and so the cuttings are sure to divide as well.