If your focus is SPS you should probably consider a bigger skimmer, if you are keeping things that like a bit higher nutrient level the 9020 will do well. I can tell you this, a local store was using a 9020 on a 180 display and everything was doing really well, I gave them a sample of the 9420 and now they are having some problems with the LPS and Anemones as the water is just too clean, the SPS are colored up and thriving though.