I had some pulsing xenia, shrooms and zooanthids in my 5.5 gallon mini-reef I tried back in 2008. That tank looked GREAT for about 6 months or so and then one day it just melted down. Our last attempt at a reef, about a year later, we never got past liverock because those damn anemone's took over the rock. It was a pain in the @$$!!

Hence why we are starting with fish this time and not worrying about corals.