As long as your lights are strong enough, you should be fine (hammer corals are lower light/lower flow anyway.) Just be prepared to keep your ca/alk/and mag at the proper levels. Basically, if you can care for a reef tank...and you can care for a nano tank...you'll be fine. The only caution I have is that...hammer corals have reeeeally long sweeper tentacles. Be careful with placement or else it'll sting everything else.