Protein Skimmers: Doing More Harm Than Good???

[MrNYCeGuy]

After ignoring a growing bryopsis population, my tank finally exploded with the algae and I was forced to treat it with a round of fluconazole (thank God for that stuff!) Part of the treatment of bryopsis is taking your protein skimmer offline for about two weeks while the medication goes to work. While monitoring my tank closely I noticed that my SPS polyps began to extend much further, colors began to pop, and my growth rates increased. What is more, is that during this time my nutrient levels actually DROPPED! Since that time (3 months) I have NOT run any skimmer, carbon, or additives (besides two-part). The only method of mechanical filtration is a small (½ gallon) HOB cheto refugium and filter floss (polyester basket media). How could this be? After doing more research and thinking through the possibilities it hit me, perhaps our protein skimmers are actually hindering our progress in the hobby, not accelerating it. Two articles written in Advanced Aquarist suggest similar skepticism.

The first article Elemental Analysis of Skimmate states “To the extent that the solid skimmate consists of microflora, then some proportion of the insoluble organic material removed by skimming would then simply be the organic components (the "guts") of these microflora. These microflora do concentrate P, N, and C nutrients from the water column, and so their removal via skimming does constitute a means of nutrient export.” The second article Bacterial Counts In Reef Aquarium Water states that “Aquaria subjected to active filtration via skimming present water column bacteria populations that are approximately 1/10 of those observed on natural reefs. The consequences of this disparity on the long-term health of the tank's livestock are not known...It appears likely that some types of bacteria are indeed "skimmable", but others are not. Thus, skimming inadvertently provides severe (?) evolutionary pressure to skew the tank's resident water column bacteria population to favor the "non-skimmable" cohort.”

While our skimmers are removing waste from the tank, is it possible that they are removing the bacteria that would otherwise be removing that same waste? Is it also possible that this entire time we have been trying to mechanically remove nutrients from our tank only to be depleting our tanks of what it really needs, a healthy bacteria population?

 

[The Aquatic Arsenal]

I agree with you about Protien Skimmers may not be needed. The one I have on a mixed reef frag system is only used a couple of hours a day. Back in the beginning of December I added a Macroalgea reactor because I couldn't seem to get phosphate levels where I wanted them. My nitrates always seemed to be around 20, which isn't terrible. After the Cheato grew a little bit, all of my nutrients were in check, and I didn't need the protien skimmer as much.

 

[NanoDJS]

Its all about balance , I have ran my system with and without , I find that heavy in /out works best for me which requires that I skim during my photo-period, when I feed corals ( at night ) lights out, I have a 6 hours nutrient uptake period before skimming. They also help to aide with aeration as a side benefit. Everybody's system is different and at a diff stage and bio-load etc , so I would say its best to have one but use it accordingly , the days of 24/7 skimmer are long gone.

 

[TexasReefer82]

Great question, I've been thinking the same.

For the last year or more I've been dosing Nitrate and occasionally phosphate to maintain measurable levels. But even then I still have a couple acros that are pale and unhappy. Reading through some of Riddle's articles it seems that corals actually prefer organic Phosphorus instead of inorganic phosphate. Perhaps what my corals want is the exact stuff I've been skimming out.

I've had a similar experience to you where after a two week skimmerless stint of fluco my tank looked fantastic - more than once, in fact.

I've recently started running my skimmer only 6 hours per day and may drop it down to 3.

 

[Turtlesteve]

I've run both ways, and found that running skimmerless did NOT lead to higher nutrient levels. I had low or undetectable P quite regularly when skimmerless, and had to start dosing NO3 and P. Back in the old days, I ran a deep sand bed and a big skimmer, and that system always had high NO3 / P in comparison.

I did have a major crash last year, due to equipment failure, and subsequent nutrient spike. This was by far the worst system crash I've ever gone through, and I got stuck in a high NO3 / low P situation for months due to algae growth. I eventually added a skimmer, which really cleaned things up and let me get the system under control again. So that's one point for using the skimmer, I guess.

My interpretation of all of this is as follows: In a healthy system, the ability of the biological filter to process waste probably increases when the skimmer is absent, so that the overall nutrient export tends to balance the input. However, in a crash scenario, the supplemental capacity to export nutrients is quite advantageous. As to why I keep having to dose P, who knows....

Steve

 

[Nano sapiens]

Its all about balance , I have ran my system with and without , I find that heavy in /out works best for me which requires that I skim during my photo-period, when I feed corals ( at night ) lights out, I have a 6 hours nutrient uptake period before skimming. They also help to aide with aeration as a side benefit. Everybody's system is different and at a diff stage and bio-load etc , so I would say its best to have one but use it accordingly , the days of 24/7 skimmer are long gone.

Going back in history is helpful in understanding the role of the protein skimmer. Back when the Berlin method started (and what can be argued was the start of the reef keeping hobby as we know it today), protein skimmers were quite inefficient measured by today's standards. Running 24/7 removed a lot less gunk that what a typical modern skimmer would remove today running that same schedule.

So yes, running an appropriately sized modern efficient skimmer for a few hours a day makes good sense for most larger systems IMO, both for not removing too much organics and for oxygenating the system.

Running skimmerless is of course an option for those who prefer the K.I.S.S. method of reefing and has been my personal choice for the last 30 years with various sized aquaria.

 

[Nami]

I actually disagree that the protein skimmer is useless for nutrient export, strictly per se.

Let's go with your line of thought that the protein skimmer removes beneficial bacteria.

I think everyone agrees that "what goes in, must come out". If you keep feeding the tank with new food, the supposedly good bacteria will take up these nutrients. But without a skimmer, will these bacteria keep growing infinitely? The nutrients in the system will keep increasing without export.

But if you tell me that you have other means of export like refugium or water change, then this topic should be titled "protein skimmer not needed when there is refugium and water changes", which makes better sense.

 

[chriss1992]

are powerheads enough to oxygenate the water ?

Going back in history is helpful in understanding the role of the protein skimmer. Back when the Berlin method started (and what can be argued was the start of the reef keeping hobby as we know it today), protein skimmers were quite inefficient measured by today's standards. Running 24/7 removed a lot less gunk that what a typical modern skimmer would remove today running that same schedule.

So yes, running an appropriately sized modern efficient skimmer for a few hours a day makes good sense for most larger systems IMO, both for not removing too much organics and for oxygenating the system.

Running skimmerless is of course an option for those who prefer the K.I.S.S. method of reefing and has been my personal choice for the last 30 years with various sized aquaria.

 

[S2G]

I have chaeto before my skimmer & the skimmer hardly runs right now

 

[Nano sapiens]

are powerheads enough to oxygenate the water ?

'It depends' (a phrase often used in reef keeping). To illustrate by extremes: Brisk flow, open top and a relatively light bioload, should be just fine without additional oxygenation. Heavy bioload, enclosed canopy with little ventilation, a skimmer's oxygenation of the water would be most benefical. Since each system is different, anything in between the extremes is up to the reef keeper to determine whether it's beneficial, or not.

 

[DangerDave]

I run my skimmer 24x7, but have it dialed back to skim on the dry side. I open it a bit occasionally to flush the cup drain.

 

[X-37B]

"Balance"
I run skimmer filter sock and thats it + carx.
Imo you need to match your skimmer to your system.
So many people buy a skimmer thats way oversize for the system they are running.
Thats not so simple as every system is different.
My skimmer pulls dark brown and thats what I want.
It wont remove everything, but I feed heavy, dont run a fuge, so my skimmer is needed imo.
Forgot to mention that I run a no water change system so skimmer is needed.

 

[Miller535]

After ignoring a growing bryopsis population, my tank finally exploded with the algae and I was forced to treat it with a round of fluconazole (thank God for that stuff!) Part of the treatment of bryopsis is taking your protein skimmer offline for about two weeks while the medication goes to work. While monitoring my tank closely I noticed that my SPS polyps began to extend much further, colors began to pop, and my growth rates increased. What is more, is that during this time my nutrient levels actually DROPPED! Since that time (3 months) I have NOT run any skimmer, carbon, or additives (besides two-part). The only method of mechanical filtration is a small (½ gallon) HOB cheto refugium and filter floss (polyester basket media). How could this be? After doing more research and thinking through the possibilities it hit me, perhaps our protein skimmers are actually hindering our progress in the hobby, not accelerating it. Two articles written in Advanced Aquarist suggest similar skepticism.

The first article Elemental Analysis of Skimmate states “To the extent that the solid skimmate consists of microflora, then some proportion of the insoluble organic material removed by skimming would then simply be the organic components (the "guts") of these microflora. These microflora do concentrate P, N, and C nutrients from the water column, and so their removal via skimming does constitute a means of nutrient export.” The second article Bacterial Counts In Reef Aquarium Water states that “Aquaria subjected to active filtration via skimming present water column bacteria populations that are approximately 1/10 of those observed on natural reefs. The consequences of this disparity on the long-term health of the tank's livestock are not known...It appears likely that some types of bacteria are indeed "skimmable", but others are not. Thus, skimming inadvertently provides severe (?) evolutionary pressure to skew the tank's resident water column bacteria population to favor the "non-skimmable" cohort.”

While our skimmers are removing waste from the tank, is it possible that they are removing the bacteria that would otherwise be removing that same waste? Is it also possible that this entire time we have been trying to mechanically remove nutrients from our tank only to be depleting our tanks of what it really needs, a healthy bacteria population?

I will start by saying I do not think they are necessary. And I do believe in SOME systems they may pull out things they shouldn't. But the idea that they pull out more bacteria and fauna then what can reproduce in a system is totally bogus. Bacteria and fauna produce WAY faster then any appropriate sized skimmer could pull out. And if they were so effective at pulling out bacteria, then why do so many tanks that run them still have bacterial blooms?

 

[Edgecrusher28]

I will start by saying I do not think they are necessary. And I do believe in SOME systems they may pull out things they shouldn't. But the idea that they pull out more bacteria and fauna then what can reproduce in a system is totally bogus. Bacteria and fauna produce WAY faster then any appropriate sized skimmer could pull out. And if they were so effective at pulling out bacteria, then why do so many tanks that run them still have bacterial blooms?

Dang this is an old thread, but staying with the topic I had a thought. If a protein skimmer can only remove un-dissolved organics, then what would be the point and or benefit of running a skimmer 24/7. If the idea of removing forms of beneficial bacteria were true, would it not make the most sense to run the skimmer for a few hours after a feeding were it serves its primary purpose and then shut it off to avoid any unintentional consequences?