Coral growth help

[Black Phantom]

I need some advice. For some reason I just cant get a lot of my corals to grow. Ones like Candy cane and frogspawn are ok as I hand feed them but the rest just sort of hang in limbo. No growth or retraction.
Anyone got any secret formulas that they would like to share. My lights. RO water, and everything else is fine. I'm not asking for much, just a masive growth spurt that will have my tank looking like something out of a magazine