Skimmers, are they really necessary?

[ReefGeezer]

The pH rose in my tank because I used limewater (kalkwasser) for all calcium and alk, and had quite a bit of photosyntheses, some on offset lighting times. Thus, my pH was always above 8.3, but got even higher when the skimmer was not running to draw in more CO2 to offset that level of CO2 consumption.

So you are using the skimmer to depress pH by adding CO2? That seems just opposite of what others are doing. They are trying to strip or reduce CO2 from the air supplied to the skimmer to keep it from depressing their pH.

 

[Randy Holmes-Farley Verified Community Expert]

So you are using the skimmer to depress pH by adding CO2? That seems just opposite of what others are doing. They are trying to strip or reduce CO2 from the air supplied to the skimmer to keep it from depressing their pH.

That’s not the only reason I used a skimmer, but that is the effect.

Folks wanting a skimmer to boost pH most often need to use lower CO2 air than in their home, so use outside air or a scrubber.

 

[Belgian Anthias]

A skimmer removes +- 30% of produced DOC. The available carrying capacity is based on the use of the skimmer in place. Without a skimmer more DOC will be available for heterotrophic mineralization producing more CO2 . More nitrate will be produced ( consuming alkalinity) this if sufficient autotrophic carrying capacity is installed.
In a balanced system produced CO2 and nitrate is used up by photo-autotrophic growth, by which everything is compensated, resulting in a stable system. In most reef systems photo-autotrophic growth is limited available.
it is not a good idea to remove a skimmer from an existing system without preemptively ensuring sufficient growth opportunities. A problem that is very easy to solve by providing sufficient remineralization capacity and adapted photoautotrophic growth in advance. The system must be conditioned to what is coming and what may be expected.

One does not need a skimmer to boost pH because pH is buffered by nature, produced CO2 is used and the use of nitrate will stabilize alkalinity. Basic marine aquarium management. In a reef tank light can not be a problem. Using a refuge for managing reducers and or producers night and day pH fluctuations can be limited to natural proportions.

 

[Randy Holmes-Farley Verified Community Expert]

One does not need a skimmer to boost pH because pH is buffered by nature, produced CO2 is used and the use of nitrate will stabilize alkalinity.

That’s a somewhat odd statement. It’s very much like saying one does not need an antibiotic to recover from an infection because your immune system does it naturally.

Obviously, the problem is when nature is not sufficiently dealing with the issue that using appropriate additional tools can help.

Skimmers are one of many tools that can help, and while it is not the only one or maybe not even the best one, it can be a relatively useful tool that is not as expensive as, say, an HRV ventilation system to bring more fresh air into the home (Reef aquarium pH is very often low due to elevated indoor CO2, not because there’s some sort of biological imbalance in the aquarium).

 

[thatmanMIKEson]

but got even higher when the skimmer was not running to draw in more CO2 to offset that level of CO2 consumption.

Does your skimmer pull outside air or have any c02 scrubbing involved?

 

[Randy Holmes-Farley Verified Community Expert]

Does your skimmer pull outside air or have any c02 scrubbing involved?

No. But I also doubt the basement air where my skimmer was had particularly elevated CO2.

 

[Belgian Anthias]

That’s a somewhat odd statement. It’s very much like saying one does not need an antibiotic to recover from an infection because your immune system does it naturally.

Obviously, the problem is when nature is not sufficiently dealing with the issue that using appropriate additional tools can help.

Skimmers are one of many tools that can help, and while it is not the only one or maybe not even the best one, it can be a relatively useful tool that is not as expensive as, say, an HRV ventilation system to bring more fresh air into the home (Reef aquarium pH is very often low due to elevated indoor CO2, not because there’s some sort of biological imbalance in the aquarium).

There is nothing odd about it.
Antibiotics kill. We do not have to deal with an infection because the immune system has failed. Using antibiotics for the wrong reason does eliminate the immune system.
I do not see any resemblance. Nothing has failed.

Or is about using antibiotics without the immune system had the chance to do what it is supposed to do?

 

[Randy Holmes-Farley Verified Community Expert]

There is nothing odd about it.
Antibiotics kill. We do not have to deal with an infection because the immune system has failed. Using antibiotics for the wrong reason does eliminate the immune system.
I do not see any resemblance. Nothing has failed.

Lol, ok, I think it’s a perfect analogy of when nature is failing to keep things where we want (we are sick or pH is too low) and an additional tool is needed, but if it does not help you understand the issue, ignore it.

 

[Belgian Anthias]

Skimmers are needed because: ?

We do not need an expensive skimmer to manage CO2, not even for the introduction of oxygen. There are cheaper and more effective options for this. If one has one, I hope it must not be used because the natural processes have failed . In most reef systems a balance between reducers and producers is not present and one can use the skimmer present as an aid, but it will not solve the problem.

If CO2 produced by heterotrophs is used up for new photo-autotrophic growth, the oxygen used up by the reducers, producers of that CO2 can be replenished. In this way the water remains saturated with oxygen and the CO2 present in the living room has little or no influence on the water quality.

Only because you use a skimmer, you need one.

 

[reaper93]

I have no skimmers, just HOB filters on tanks. Not ideal but it gets the job done

 

[\m/reefsnmetal\m/]

Skimmers are needed because: ?

We do not need an expensive skimmer to manage CO2, not even for the introduction of oxygen. There are cheaper and more effective options for this. If one has one, I hope it must not be used because the natural processes have failed . In most reef systems a balance between reducers and producers is not present and one can use the skimmer present as an aid, but it will not solve the problem.

If CO2 produced by heterotrophs is used up for new photo-autotrophic growth, the oxygen used up by the reducers, producers of that CO2 can be replenished. In this way the water remains saturated with oxygen and the CO2 present in the living room has little or no influence on the water quality.

Only because you use a skimmer, you need one.

He did not say skimmers are needed. He actually mentioned that skimmers might not even be the best tool for managing PH.

 

[Randy Holmes-Farley Verified Community Expert]

Skimmers are needed because: ?

We do not need an expensive skimmer to manage CO2, not even for the introduction of oxygen. There are cheaper and more effective options for this. If one has one, I hope it must not be used because the natural processes have failed . In most reef systems a balance between reducers and producers is not present and one can use the skimmer present as an aid, but it will not solve the problem.

If CO2 produced by heterotrophs is used up for new photo-autotrophic growth, the oxygen used up by the reducers, producers of that CO2 can be replenished. In this way the water remains saturated with oxygen and the CO2 present in the living room has little or no influence on the water quality.

Only because you use a skimmer, you need one.

If you have cheaper and more effective options for gas exchange, as well as export of organics, then use them.
I happen to think a skimmer is very good at gas exchange and removing various types of organic matter, and I like them for those reasons.

Natural processes in my tank failed to keep my pH where I wanted it. A skimmer solved that problem. Yes, nature failed, and humanity saved the day. :)

 

[Randy Holmes-Farley Verified Community Expert]

Only because you use a skimmer, you need one.

That is an incorrect conclusion.

With the skimmer I had no problem.

When I removed the skimmer as a test, I had a problem.

When I returned the skimmer after weeks of having the problem, it went away.

The skimmer is the hero, not the villain of my story. :)

 

[fryman]

It's interesting that the discussion is focussed on aeration. A skimmer happens to do so but this is not the intended purpose of a skimmer. Most people buy a skimmer for export of organics. Aeration is just a side effect.

A skimmer exports organics, and this is usually very useful for reefers.
A skimmer also aerates the water, which can be useful as well.

Beyond that I don't really get why there's much debate. There are other ways to do these things but a skimmer is a good tool if these effects fit your needs. There are other ways to accomplish these goals as well.

 

[Belgian Anthias]

That is an incorrect conclusion.

With the skimmer I had no problem.

When I removed the skimmer as a test, I had a problem.

When I returned the skimmer after weeks of having the problem, it went away.

The skimmer is the hero, not the villain of my story. :)

If the logical precautions are not taken, removing a skimmer will cause problems.
Marine aquarium basics tell us we have to condition the system for what is coming if big changes are planned. The remineralization capacity must increase to remove more DOC, the nitrification capacity must increase to remove more ammonia, the biological oxygen demand, BOD, will increase needing more oxygen, CO2 and ammonia production will increase. Without precausions it is not a good idea to remove the skimmer.
You need the skimmer because you use one. A system with a skimmer is not conditioned for not using one.
What if the skimmer suddenly fails?


Using AAM, active aquarium management, a balance between reducers and producers is found, the system will be able to adjust to any situation, with or without a skimmer in use, also in situations where the skimmer suddenly fails.

You had a problem after removing the skimmer. Only one?

 

[WWC Verified Sponsor]

Skimmers are a very useful tool to have. You do not have a run a skimmer 24/7 but they do help keep a healthy tank. If you do not run one always make sure you keep up with water changes. Another important thing is to consider tank size.

 

[Karen00]

I don't think skimmers are needed in a lot of cases but every tank is different. I've been running my new tank for a year without one but... (Insert suspenseful music here)... Now that the tank is maturing and the inhabitants are growing (fish and corals) I find I'm feeding more and this causes DOCs to accumulate so much faster. When I started my tank I could get away with changing the water every two weeks. Now I'm lucky if I get four days before the water starts to look heavy and I get a mulm type buildup on everything. I had bumped up my water changes to weekly but now I'm twice weekly and I'm in search of a tiny skimmer (my tank is just a 5g AIO type). I hope to find one small enough to go in one of the back chambers. I might try adding a hob fuge first to see if that helps purify the water but I think a skimmer will still be needed.

I think I'm a skimmer convert. :-) For all those folks not running skimmers how do you keep your water clean? Are you doing daily water changes? Are you running the water through elaborate filtration systems?

 

[Randy Holmes-Farley Verified Community Expert]

You had a problem after removing the skimmer. Only one?

Correct, I only noticed one problem: inadequate gas exchange.

Returning the skimmer to action solved it.

It makes no sense to me to claim that if I’d never used a skimmer, that the pH would never have been high, or that somehow the breakdown of organics will naturally provide just the right amount of CO2 to offset the demand caused by hydroxide.

 

[fryman]

I think I'm a skimmer convert. :) For all those folks not running skimmers how do you keep your water clean? Are you doing daily water changes? Are you running the water through elaborate filtration systems?

My first tank had no skimmer but a ton of soft coral. Things like zoas, palys, clove polyps and xenia grow very fast and seem to suck up nutrients. I also had a refugium and grew chaeto. I'd fill a 5gal bucket every week or two and trade it in at my lfs.

 

[Karen00]

My first tank had no skimmer but a ton of soft coral. Things like zoas, palys, clove polyps and xenia grow very fast and seem to suck up nutrients. I also had a refugium and grew chaeto. I'd fill a 5gal bucket every week or two and trade it in at my lfs.

Ya, I'm thinking of adding a fuge. Everyone in the tank doesn't seem to care that there's no skimmer but visually the heaviness of the water and that mulm buildup is not appealing. :-) My soft corals love the extra nutrients as well! just like yours. Haha. Maybe a fuge alone will help or just a skimmer or both. :-) I need something to help clarify the water. Water changes totally clears it up but I don't want to start doing more than twice weekly.