No trace elements, just a great deal of light, good water conditions (water changes are a good idea) and occassional feedings (or feed the fish/tank and let it consume some of that).
As for aggressiveness, all anemones _can_ eat fish, but most fish know to avoid them. The only real worries as far as the fish go are blennies, hawkfish, and any other types that tend to settle onto something to rest.