i have 75g tank 29g sump with refug i have nova t5 lighting 8 bulbs(getting ready to order reflectors)ive had tank about 1 1/2 years or so.i have tang and cardnial fish 2 emerald crabs,sea urgent,and a bunch of cleaner crabs and what i think is a pom pom crab.what my ? is is what are some good corals for me to get started with that i would want to keep and how do they eat. do i feed them or do they get what they need from light and or water.really want some color. and i do have about 100LBs of live rock and 4" sand bed. please help