How Do They Grow
 

i know there are efficient ways to multiply the volume of corals any body got any hints or tips !??? chems or foods or just time thanks every one !

Your question is pretty broad what kind od corals?

i have a frog spawn and a trumpet coral i think alot of zoo's do they spread on there own ?? lots of other species i want to grow but not very aware of conditions needed for optimal growth

Feeding, water quality, lighting, and time all affect growth. Once your corals adjust to your tank they start to grow.