If I were asked what a solution might be, I would propose the following. Use the most efficient skimmer possible and one that is capable of maintaining high water quality when used constantly. Assuming that they do provide some amount of oxygenation, even if minimal, I would then begin shutting off the skimmer during the day for a few hours and measure tank condition visually and through testing for several weeks. If water quality is maintained, I would increase the number of hours the skimmer is off, and wait again, continuing this process until the maximum number of hours is reached where water quality and tank health remains the same without the use of the skimmer. I would also opt for daylight discontinuance since oxygen is less of a problem when photosynthesis is occurring, and since most aquarists tend to feed fish and other products like phytoplankton during the day. This way, residual foods will not be removed for at least several hours. Some aquarists may even find that they can discontinue skimmer usage entirely (I think this likely, especially if activated carbon is employed).
