hmm a sterile system vs a natural system its apples and oranges. i prefer the natural system the only problem with hitchhikers is the aquarist. if you dont rush to set up a system you should have plenty of time to eradicate most of the (pests)?????? before you finish out the tanks coral and fish populations plan it out then plan some more. just how long does it take the average aquarium to reach a point when you feel its finished (6years ) i just recently added my last fish to my 180 gal soft coral tank nothing good happens quickly in this hobby. after six years i feel my tank has reached a balance and yes i have aptasia hence the final addition to the tank and the copperband is doing his job with gusto