I have a 30G 3 chamber top flow with 1 100W grow light CFL. The cheato and coralline love the CFL more than the old Hydra 52. The center DT overflow and the secondary high-flow overflow drop into #1 with the skimmer. The high-flow is only used during water polishing and detritus cleaning. I got through a LOT of 100-micron felt during that. #2 has fine sand, live aragonite and then chunks of rock. There's a 7" ball of cheato in there and a naughty azure damsel. He killed the second one I jailed in chamber 2. Oh well, it was better than tossing them in the yard. My Apex probes, return pump and reactor source lines are in #3. There is a foam sponge hanger between #2 and #3 that gets a layer or 100-micron and 2-layer floss for polishing. The amphipods like that setup so I always have to make sure to flick them off when I change it. A Skimmz reactor flows from #3 to #1 with carbon pellets on super-low-flow. I have an additional large filter cartridge that recycles in #3 for when I need po4 scrubbing or to remove detritus that makes it into the return chamber during sump overflow.