I agree with the above comments - if you want to keep starfish, I recommend either Brittle Starfish (*not* the Green Serpent Starfish, Ophiarachna incrassata, as it's a known fish-eater, but pretty much any other brittle starfish is safe), or, if you want a true starfish, Aquilonastra Stars (known in the hobby as "Asterina Stars" - the ones mentioned above).
There are currently 32 accepted species in the Aquilonastra genus - some of them seem to be safe while others are known to eat zoas (whether they mean to eat them or not is still unknown); a few, rare species may also occasionally go after a different kind of coral, but it's incredibly rare.
With you wanting zoas, I'd suggest brittle starfish.
Brittle starfish are actually Ophiuroids, while true starfish are Asteroids; brittle starfish typically do well in our tanks, and can be sustained readily on things we feed our fish. True starfish, on the other hand, typically fair very, very poorly in our tanks, usually starving within ~8-13 months. To overgeneralize a bit, there are basically two kinds of true starfish: predatory stars (generally not reef-safe, as they may eat corals and/or other critters in the tank; the ones that are comparatively easy to feed adequately are typically temperate/coldwater stars) and biofilm-feeders (generally reef-safe with a few noteworthy exceptions - like the Chocolate Chip Starfish - but borderline impossible to feed adequately at this point).
addictivereefkeeping.com
