Lots of flow, no substrate, no algae in system, agressive wet skimming and lots of well fed fish who through their "excretory activities" feed the SPS. Kalk topoff and calcium reactor to fuel the SPS growth. 10k lighting.
I'm sold on ozone as well.
I'm currently experimenting with the addition of vinegar to my Kalk topoff, figuring the bacteria need some additional organics to do their thing--so far, the results have been positive.
Coming up on two years with this method--I've never had better success with SPS. Two years was about the time I saw some disturbing changes with my DSB/chaeto refugium systems, so only time will tell if my current system is "durable".
John