Looking good. My opinion: if that green stuff looks like film instead of hairy/fuzz, don't do anything different. If you had live rock or even painted dry rock, you probably would have barely noticed any film algae on the rocks. If it is hairy/fuzzy, reduce your peak photo period by 25% since you have no corals and perhaps consider feeding a bit less. Otherwise, don't do anything else different--and prepare for the tank to start looking uglier (not that I think it looks anywhere near ugly right now---so you're going to have a shock if you think it's ugly now!).