if you use enough lr and ls then the bio wheels are usually not necessary cuzz the lr and ls will take care of the bio filtration. a protein skimmer is usually the ideal method of mechanical filtration in a sw setup, but i have also heard people having a lot of success using a canister filter. if you plan on getting any corals in the future then i dont recomend the bio wheels. maybe someone else can go a little deeper on the subject for you. HTH