Real nems = real problems in new tanks. New tanks are rather volatile in the first year, and even expert aquarists hesitate to put nems in new tanks. They need excellent lighting, pristine water conditions, and stability to thrive. And unlike a coral or fish that dies, a nem will nuke your tank on its way out. When a nem dies, it releases its nematocysts (stinging cells) that then float everywhere in your closed environment, killing everything in their path. In the ocean that doesn't cause a problem because they are quickly diluted in the ginormous water volume that is, well, the ocean. But in a closed system of a fish tank, especially a small one, everything will die. :death:
Just my :twocents:, but I would see if you can take those nems back to your LFS. And if you're worried that the clowns need the nems, stop worrying. Clowns will choose practically ANYTHING as a host, and they don't tend to host those nems anyway. So see if your LFS will let you trade the nems for an easy keeper coral like a Duncan, Fuzzy mushroom, or xenia that can make a suitable "house" for the clowns and not kill your tank! Other than that, your tank looks GREAT, and I really like your stock choices.