Of course, without a doubt I follow you. Fortunately, I have had the same 200 pounds of live rock for about three years. The sand bed is getting established again. But, the tank is quite established. I have just recently been adding corals again. It still has a little time to go before it gets self sufficient like you say. I am still raising the sand bed, getting water flow and everything straight. But, as far as water quality, this thing is great. I want to play it safe though.