Good lighting- MH and T-5 seem to give you the most bang for your buck as far as intesity and bulb life. 10k-20k range will give good overall coloration. Choosing the Kelvin rating really just comes down to preference for overall tank color.
Maintain a good PH, Alkalinity, and Calcium balance and overall stable parameters.
No extra feeding or "magic" additives are necessary if you feed your fish and inverts and do regular water changes.
Zoanthids also like good indirect randomized flow. The flow should help remove debris and detritis that settles between the polyps, but not so strong that polyps can't stay open.
Good luck