If you want coral to grow fast and healthy, you need to have a stable and mature system and keep the water well maintained. There are a few minor things that can be done, but just like children, you can't make them 'grow' faster than 'normal'. Coral isn't a plant, it's an animal, and there is little you can do to make it grow other than give it the correct environment and food.
Yes, SOMETIMES adding a bit more light, or a slightly longer photo period, or increasing the Ca, alk & Mg can help, or changing the flow. But if you are already providing the coral with a good environment, there is little more you can do.