My tank is in a constant state of flux as I change/upgrade everything, but here is a list of things that I can remember:
-swapped out modded maxi-jet for 2 tunze nanostreams (and then modded them too:grinyes

-added phosban reactor w/GFO
-Tee'd the return line to add more flow to refugium
-pH monitor
-put a filter sock on the drain line into the sump to filter particulates (I have two of them and swap and clean them every week)
-added air pump w/ airstone to refugium (seems to keep pH up a little and fosters growth of chaeto, this may all be in my head, I added this on a whim and it seems to produce the desired efffect, but I am not certain)
-tried numerous fish foods, coral foods, additives and feeding/dosing schedules
-ran out of room, so I set up a 50 gal frag system in the basement w/ MH's, skimmer, and all the trimmins :shakehead: It just never ends.....
Did I mention that I have only had this tank for just over one year??