I'm not the zoa experts of some (a lot), but I supplement iodine (I test with the Red Sea Pro) and if it shows under .06, I'll drop in a drop of loguls. I also have my zoas/corals on a feed routine. Every couple of days I take a cube of cyclopeze, oyster eggs, and baby brine and blend it with some RO water until it's pretty much just a cloud. I add it to the tank, leave the pumps going for 6 - 10 seconds to disperse it and then shut all flow off. The tiny particles seem to float down to the zoas and other softies and LPS. After about 10 minutes I turn the flow back on and let the skirts and feelers snag some. So far so good, and nitrates are under 3 ppm so it's not upsetting the balance of my tank. I prefer this to target feeding as when I "blow" out the food a lot of times the force no matter how softly I try, shuts the zoas.