You are overlooking several fundamental things. FO systems often have more fish stock than a reef and may be fed more heavily. Not all the time, but a good portion of the time. Second, most FO tanks don't have the same illumination and therefore won't be getting the same amount of light, meaning less oxygen available through photosynthesis. Again, in many cases, FO tanks will have less oxygen as a result. My reef supersaturates with respect to oxygen due to photosynthesis--a protein skimmer can't usually do that, but photosynthetic activity can. Sure, not every FO system will be under the same circumstances, but in most situations, you nor I don't know enough to decide that for the poster. Assuming the above issues don't apply can potentially cause more harm than good. I am glad your FO tank doesn't suffer from these issues, but many do. And, out of experience, most people do not even test their DO. You can't assume everyone's tank is just like yours, as that leads to trouble quickly.
That's the last I'm going to say on the matter here, as it is it seems to be drifting away from the intended purpose of this thread. If you'd like to discuss more, you are more than welcome to start a new thread or contact me via pm.
