Is it feasible to remove the skimmer? Could it solve the decades-long problem of nutrient accumulation?

[Nano sapiens]

One of Ken Feldman's articles from Advanced Aquarist references the '35%' DOC removal number:

https://reefs.com/advanced-aquarist/

(under 'Author', scroll for 'Ken S. Feldman')

I see the skimmer as being potentially useful in large reef aquariums with a relatively heavy bioload. There is evidence that skimmers selectively remove certain types of bacteria and not others and also maintain bacterial counts around 1/10 that of natural reef levels, but whether this is potentially detrimental long term has yet to be established (to the best of my knowledge).

Many smaller systems run just fine without a skimmer. Not many run for a very long time (and the reasons are many), but it's certainly not due to any size limitation.

12g, 13 years (no skimmer or other mech/chem filtration):

 

[Belgian Anthias]

Not using a skimmer does not mean DOC will accumulate. it means all produced DOC may be reminerelized and removed without being selective. One does not need a skimmer for maintaining the water quality needed.

A question to ask is what is best, the fact essential inorganic nutrients which in the present cercumstances can not be used by growth may accumulate or the fact everything is reminerelized and can be reused for growth.

Those who use algae filters an scrubbers are often confronted with bleaching leaves and not growing algae, this when having a high nitrate level.

Some are not able to lower the nitrate level by adding a carbohydrate based product, often leading to overdosing.

In a closed system, the growth and remineralisation rate is responsible for clean water, with or without a skimmer. The skimmer has a huge influence on growth and water quality.
A question to answer is if this influence on water quality is positive or negative.

Efficient growth can not be maintained without sufficient availability of all essential buildingmaterials, efficient remineralisation. The result is very clean water without accumulation of essential nutrients , limiting the risks for sudden uncontrollable outbreaks of dominant growth.

 

[HuduVudu]

It is a little bit strange to me that people are suggesting that you won't get good SPS growth from a skimmerless system. I find this to be confusing. My SPS growth is good. Though it is hard to tell from the picture I have two named SPS (I seriously don't care about the names so I forgot) in my tank. They are as expected very fast growing. The are living up to their rep in my tank. I also have many slow growing SPS that area thriving. Plus the stylo as mentioned they are pretty easy.

I would not characterize my tank as low nutrient, though I do struggle to keep the nutrients. One of the things that I have found to be really important in my tank is Iron. I dose Iron filings daily. This has been really impactful in me growing things. I am also noticing that my Magnesium usage is insane. I am using the Magnesium Nitrate to deliver Nitrates.

FWIW

 

[jda]

I think that these questions and argument is too simplistic. Sure, you can do fine without a skimmer, but you have to have another way to export the organics. This can be easy with a mature tank with rock and sand where anxoic bacteria can turn nitrates into nitrogen gas like it is their job (since it is their job). It is also fine for aragonite to bind phosphates and keep them out of the water column for a while - fools gold since the bill comes due. Fuges could work as well. I also see people cut back on feedings when they don't have good export which hurt the corals. It can work and work well, but there is more to it than discussed here.

I use a skimmer since I want my rock and sand to stay relatively free of P and also so that I can feed the heck out of my fish to keep available building blocks in the water column for my corals to thrive. For me, no heavy import and heavy export without skimmers. I use multiples, actually. I could do fine without them, but I am too lazy to do it since my methods would have to change, in particular a way to remove phosphate.

 

[Spare time]

Those BTA'S... oh my! Nice work. Been thinking on picking one up, however I have a rather large Long Tent who hasn't wandered in about 9 months...but, potential for firestorm..... thoughts?

I love long tentacle anemones. You can have both. They could end up wanting the same area of the tank but its worth a try if you want both.

 

[HuduVudu]

I use a skimmer since I want my rock and sand to stay relatively free of P

At some point you reach saturation on P with the rock, what time frame do you think that that is?

 

[jda]

It is not a time thing. The P binds and unbinds with the aragonite based on the water level. The aragonite will bind more and more as the water lever gets higher and can become quite a reservoir. It can also bind very little and become a buffer if the water level is kept low.

I want mine to be a buffer in the 1-5 ppb range of water level to keep my tank from never hitting zero but also not be high to growth limit anything.

 

[Borat]

After taking one look or smell at what a skimmer pulls out of the water, I don't know how anyone could run a tank without one.

I ran my tank skimmerless since it's day one... never owned a skimmer. Never need to clean the tank - everything is recycled by algae..

I run ATS though - as refugium is not very large (but I have chaeto in refugium with some other macro algae)...

 

[ApoIsland]

It is a little bit strange to me that people are suggesting that you won't get good SPS growth from a skimmerless system. I find this to be confusing. My SPS growth is good. Though it is hard to tell from the picture I have two named SPS (I seriously don't care about the names so I forgot) in my tank. They are as expected very fast growing. The are living up to their rep in my tank. I also have many slow growing SPS that area thriving. Plus the stylo as mentioned they are pretty easy.

I would not characterize my tank as low nutrient, though I do struggle to keep the nutrients. One of the things that I have found to be really important in my tank is Iron. I dose Iron filings daily. This has been really impactful in me growing things. I am also noticing that my Magnesium usage is insane. I am using the Magnesium Nitrate to deliver Nitrates.

FWIW

I agree that my SPS grow very well in a skimmerless tank also. Although it appears you and I both keep very easy SPS.

I have never seen a really nice acro tank without a skimmer. Whether that's because they don't try, or its just not possible without getting that extra 35% out and whatever else others have mentioned, I don't know.

Hoping someone going skimmerless with a really nice tank full of acros can post some details. If that person exists....

**Edit to state that I have tried to do a few diff acro frags in my skimmerless tank and I have failed both times.

 

[HuduVudu]

It is not a time thing. The P binds and unbinds with the aragonite based on the water level. The aragonite will bind more and more as the water lever gets higher and can become quite a reservoir. It can also bind very little and become a buffer if the water level is kept low.

But at some point you would imagine that some sort of saturation would occur if a constant source of P is added to the water. I guess we would have to know the amount of that P, but in my mind there should be a point where one would notice changes because the aragonite has reached it's limit.

 

[HuduVudu]

Although it appears you and I both keep very easy SPS.

Stylo is very easy to keep, but it isn't the only SPS in my tank.

I think it would be good to have an agreed definition of easy. Right now I don't think our ideas are lining up.

Can you describe what you are thinking might be harder to grow in skimmerless tank?

 

[jda]

The P can unbind from the aragonite if the water level gets lower. Nothing is permanent unless the calcium carbonate structure is still growing like in the case of a living coral and it get locked in with more growth on the outside that doe not expose the inner structure. The sand and rock never has to "fill up," ever, and can work in perpetuity if well cared for.

FWIW, GFO and Aluminum Oxide (phosguard) acts in the same way. The bind is not permanent, so if your water column level drops, the GFO and AlOx will also unbind P back into the water... which is why it is a good idea to change those media if you change some water.

 

[ApoIsland]

Stylo is very easy to keep, but it isn't the only SPS in my tank.

I think it would be good to have an agreed definition of easy. Right now I don't think our ideas are lining up.

Can you describe what you are thinking might be harder to grow in skimmerless tank?

When I refer to easy to keep sps corals I am talking about everything that is not an acropora. And I have seen a couple of thin branching type acros is skimmerless tanks, but not the really thick beautiful acros in the tanks that make you say wow.

Sorry I can't give a more scientific answer. I just don't know anything about acros as I have only failed in my couple attempts years ago so basically gave up on those.

 

[HuduVudu]

Sorry I can't give a more scientific answer.

LOL, I am not one of those Science(TM) types. Your honest experience is all that I am after.

I just don't know anything about acros as I have only failed in my couple attempts years ago so basically gave up on those.

I have worked out several things in my tank, and I have some acros that are doing very well. They are not seen easily in the picture. They are not big yet because I have just gotten the Alk Ca problem under control (thx to JDA). I just don't have the time under my belt (yet) to show large versions of those corals.

 

[jda]

This totally could have been mentioned, but skimming is also one of the absolute best ways to remove toxic metals and other nasty substance from the tank since they often bind to waterborne organics. You can do this in other ways as well, but if you are not skimming, you should have a method for this.

Every time you feed, nearly all foods have trace levels of toxic metals that can build up if not removed... among other sources.

 

[ApoIsland]

If Jda keeps posting here I will have to set my skimmer up again. I'm not looking forward to that...

 

[HuduVudu]

This totally could have been mentioned, but skimming is also one of the absolute best ways to remove toxic metals and other nasty substance from the tank since they often bind to waterborne organics. You can do this in other ways as well, but if you are not skimming, you should have a method for this.

Every time you feed, nearly all foods have trace levels of toxic metals that can build up if not removed... among other source

With the very important caveat ... water borne organics. I would be curious to know how many of the toxic elments and also how many of the desirable elements that are caught up and removed this way, if at all.

I luv ya JDA but this one I am not really buying.

 

[jda]

You can skim out some desirable stuff too, for sure. Most metals have strong binds to organics - there is a hyperlink to a source in the article below that is another good read. You can believe Dr. Holmes-Farley if you don't want to buy it from me:

http://reefkeeping.com/issues/2006-08/rhf/index.php

 

[Pntbll687]

The role of a skimmer?

My father had a saltwater aquarium in the early 1970s, based on Frank De Graaf's book, manual for the tropical marine aquarium, published in 1969. The aquarium was equipped with a counter-current skimmer. Since then, a skimmer was always in use. What has been established is that accumulation of inorganic nutrients such as nitrate and phosphate has been a perennial theme since then. However, that does not make sense, as the nitrogen is naturally constantly exported through denitrification and in fact a deficiency should occur if natural marine food is used. It is possible that food provided contains far too many of these substances, so that not everything can be used up and left behind due to new growth. Such nutrients then have a very low C/N ratio and usually contain an unnaturally very high protein content.

One can NOT keep fish in a small closed environment without exporting what of the added food was not used by the fish. A skimmer only removes +- 35% at best. of biological waste, whether dissolved or not. A mechanical filter only removes undissolved organic waste. Nothing is removed from what is not in the water column. If all goes well, there is sufficient remineralization capacity and growth, the total bio-load will increase constantly, if not regularly harvested. By using a skimmer, some of the inorganic nutrients and trace elements already present cannot be used up through growth.
Fish are fed and +- 85% of the nitrogen content of the food ends up in the closed environment. Mostly as inorganic nitrogen compounds which are not removed by a skimmer. To remove this nitrogen, of which +/- 15% will escape through natural denitrification, most of the TOC and DOC produced by the fish must be able to be remineralized and reused through growth. This is NOT possible when using a skimmer. Therefore, a skimmer creates an imbalance and accumulation of inorganic nutrients.

Disruption of the nutrient balance by the skimmer makes it impossible for everything to be used up by growth and harvested as needed. Certain nutrients and trace elements can slowly build up in this way to a toxic level.
Removing the skimmer does not restore the existing nutrient imbalance it has created during the period it was in use. This can be corrected by active algae management, AAM

Starting a new system without skimmer?

A coral holobiont will produce CO2 and other inorganic nutrients used by the symbiodinium, a result of remineralization of the DOC available there. Corals are able to supply their holobiont with organic matter and regulate the supply of DOC by excreting mucus. In this way the production of sugars by the symbiodinium is also regulated, a supply of sugars that the coral eagerly uses. A high level of dissolved organic substances in the surrounding water makes it impossible for the coral to regulate the supply as required. Therefore, dissolved organic matter (DOC) levels should be kept as low as possible where corals grow. In the ocean, the level of nutrients present in the surrounding water may be very low, but the supply is inexhaustible.

In an aquarium there is a constant production of DOC.
In the absence of a skimmer, more DOC is produced and more DOC must be remineralized, and more new growth must be harvested to keep the bio-load in check. But the nutritional balance can be restored, nutrient accumulation can be prevented.

Is it feasible to remove the skimmer? Could it solve the decades-long problem of nutrient accumulation?

This was a really long way to say "do I need a skimmer"

And the answer is no, you don't need a skimmer.

I had to take my skimmer offline on my 180g tank, I couldn't keep nitrates in the system with the skimmer on.

As long as you have a way to export nutrients like water changes, macro algae, bacteria, then there's no absolute need for a skimmer.

 

[HuduVudu]

You can believe Dr. Holmes-Farley if you don't want to buy it from me.

Ummm ... I will buy it from you. You are more reliable.