no clarification needed, IMO, you need no filtration(standard mechanical)
th lr and ls, is the filter and cleaning system, even from teh start, once cycled, it will do the job, along with a cleaning crew and a skimmer, that is ALL you will need, PERIOD,
ed r is doing a great job of explaining and i agree, only to add that when you clean a filter or change the filter media, you only disrupt things again and again, possibly creating a mini cycle, by taking bacteria out of the equation too, MEANING less stability in the system you have
i just set up one for my boss at work,
i cycled the tank, with sand adn shrimp, then added lr, then after all was stable(and done cycling and curing), i turned on the skimmer and added fish, the system is only about 4 months old, and is beaustiful, and we have nitrates under 20, with somewhat conservative stocking(i would have gone a little lighter, but you know bosses, and worse yet, mine is a woman, you know all the pretty colors she wanted), anyhow the tank is done except for her corals which we are deciding on now, while i get teh lighting around and build a canopy for it
note: teh nitrateds could be a little lower but i am pleased tehy are tehre in such a new system with that fast of a stocking, and no algae yet(starting to grow), and the dsb is not fullly establishd and working yet either