You shouldnt have a problem with one. I have a BTA in my 29 biocube and its doing well all stock lighting. Anemones should move around alot at all once they have found where they are happy. Water quality is extremly important, and so are trace elements Iodine, alk, calc, all need to be tested unless you do weekly water changes. The care they require is equal to that of a reef tank with most soft corals. As for lighting the stronger the better however they can survive under the stock PC's. The haitian anemone you speak of def needs strong flow and remember the size of the animal is deceiving. Mine can get to be a little lager than a golf ball which doesnt happen often, but when its inflated it will be about 3.5" across. Good Luck.