I like the idea of a turf scrubber may implement that into the next acrylic sump I build. I put in 3 4" filter socks in the sump I'm running now and it's kinda meh. I personally found the socks to be more hassle than they were worth and no longer run them, I do however move about 4k gph through my sump so it stays clean and keeps particles in suspension so my skimmer can remove them. I designed my sump so that all the drains dump into one end overflowing into the filter socks then through into the skimmer chamber and finally into the return pump chamber. From the return chamber water is pumped back to the display and to a 25 gallon refugium on the other end of the sump that overflows back into the pump chamber. A lot of reefers argue that sump turnover only needs to be 3-4x water volume or no more than your skimmer can handle per hour assuming that if you match the sump flow rate with the skimmer flow rate all of the water passing through gets skimmed. Years ago when I followed this train of thought my sump stayed dirty, now with high flow in the display and high flow through the sump I find that everything stays cleaner which means less maintenance for me and clear water even without the use of filter socks. My skimmer pulls some thick nasty gunk out this way too, it's been so thick you could mold it like clay. hth