Hennie, please can you gives us your thoughts on this exact below:
"Myth 17: You can never skim a tank too much.
Yes, you can. Far too many works have dealt with various aspects of protein skimming. I still feel there is too little information on exactly what, how much, and how effectively foam fractionation affects various components of the water column of reef aquaria. For the most part, protein skimmers are employed as water quality control devices to maintain low levels of organic and some inorganic materials, notably compounds containing nitrogen and phosphorous commonly linked to degraded water quality not conducive to the growth of many reef species such as corals. Whether or not they are used secondarily for other questionably useful purposes such as elimination of toxins or increasing oxygenation is another matter. My point is that once nutrient levels are low and conducive to a healthy aquarium, and until other secondarily important aspects of protein skimming are experimentally validated and quantified, any skimming over that required to maintain low levels of organic and inorganic pollutants is overskimming. Why? Because if the water is cleared of those things that are detrimental, it is also likely to be equally cleared of things that are beneficial. Given the now well-recognized limitations of providing large amounts of food without a corresponding decrease in water quality, skimming as little as possible while maintaining the aforementioned high water quality is only pragmatic. There is no advantage to a constantly stripped water column in all but a very few specialized situations.
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).
Potential: Minimal to serious. In the best cases, continuous skimming results in relatively healthy tanks that are considered successful by most standards. In the worst cases, organisms perish because of the lack of available foods in the water column. In most cases, the results are a "sterile" looking tank with little alive but corals and coralline algae. Corals tend to appear weakened and, for lack of a more accurate description, not robust.
Distribution: Extremely widespread. There are many who employ alternate means of tank filtration, and these are usually the same people who appreciate the obvious differences in allowing more material to remain in the water column without compromising water quality. Foam fractionation use is both desirable and extremely widely employed, but as with other things should be employed properly and with a judicious purpose."
Source: Mything the Point, Part Three: Conclusion - Reefkeeping.com
"Myth 17: You can never skim a tank too much.
Yes, you can. Far too many works have dealt with various aspects of protein skimming. I still feel there is too little information on exactly what, how much, and how effectively foam fractionation affects various components of the water column of reef aquaria. For the most part, protein skimmers are employed as water quality control devices to maintain low levels of organic and some inorganic materials, notably compounds containing nitrogen and phosphorous commonly linked to degraded water quality not conducive to the growth of many reef species such as corals. Whether or not they are used secondarily for other questionably useful purposes such as elimination of toxins or increasing oxygenation is another matter. My point is that once nutrient levels are low and conducive to a healthy aquarium, and until other secondarily important aspects of protein skimming are experimentally validated and quantified, any skimming over that required to maintain low levels of organic and inorganic pollutants is overskimming. Why? Because if the water is cleared of those things that are detrimental, it is also likely to be equally cleared of things that are beneficial. Given the now well-recognized limitations of providing large amounts of food without a corresponding decrease in water quality, skimming as little as possible while maintaining the aforementioned high water quality is only pragmatic. There is no advantage to a constantly stripped water column in all but a very few specialized situations.
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).
Potential: Minimal to serious. In the best cases, continuous skimming results in relatively healthy tanks that are considered successful by most standards. In the worst cases, organisms perish because of the lack of available foods in the water column. In most cases, the results are a "sterile" looking tank with little alive but corals and coralline algae. Corals tend to appear weakened and, for lack of a more accurate description, not robust.
Distribution: Extremely widespread. There are many who employ alternate means of tank filtration, and these are usually the same people who appreciate the obvious differences in allowing more material to remain in the water column without compromising water quality. Foam fractionation use is both desirable and extremely widely employed, but as with other things should be employed properly and with a judicious purpose."
Source: Mything the Point, Part Three: Conclusion - Reefkeeping.com
