Your best bet is to just give them good light and leave them be. If you have fish or other critters pooping in the water teh zoas are eating fine. My only suggestion is to try different lighting intensities. Ie. Some zoos grow well with high light, while others (tubs blues, for me) grow better under less light. Also give them good flow. Zoas can handle pretty good flow, which will just bring more nutrients to them.
The only exception in my opinion is palys. Some palys can get big enough to actually eat mysis or brine, and in that case feeding them can drastically accelerate their growth (I tried it successfully with green button polyps)
But also keep in mind I am a supplement minimalist. I dont dose/feed anything that I dont feel is absolutely neccessary to help avoid any troubleshooting problems.
