hey cow,
I moved your thread to the into forum for now.. if you hang out here for a bit, i will set you up with your own private forum...
As for feeding corals, i dont do it unless i can see them eat/digest/take in... so, for zoas, some do and some dont...
you will see when you feed your fish.. if some fish food hits the zoa, and it closes up, and then is gone in a fe minutes, then you know it eats... Some folks know that some types do in fact eat, and you can ask them if they eat, or if they should be fed... typically, if they do eat, then they probably propagate faster... I know my 'purple deaths' will grow 'baby' after baby, if i fed them daily...
I have some 'cinnamon polyps' (okay, go look them up), which also eat and grow... my frags hve doubled in the 6-12 months that i have had them.. and they now look like colonies, and take up a 6" sq area... (maybe 50 polyps?)
Other corals also eat, lps... but not all...
I would not 'feed the tank' with coral food that you find at the lfs... waste of money.. same with other additives... dont add anything unless you can test and empirically determine it is lower then what is best for the corals/marinelife