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Should I Aerate My Aquarium?

Yes you should aerate your aquarium even if you don’t aerate it 24/7 it is a good idea to add some oxygen to the water periodically. One good reason to ensure the tank gets aerated is if the aquarium has a small surface space such as an octagon style tank.

Another reason is if you have quite a few live plants as the plants will use up the oxygen that your fish require.

Another great reason is if you have maxed out your bio-load in the tank with as many fish you could possible keep in one tank, this can require you needing to get more oxygen into the water somehow.

What is Aeration in an Aquarium?

  • Aeration in an aquarium is the process of adding oxygen to a tank.
  • Somehow whether you have a bubbler (air stone) or air circulating into a filtration system air is being added to the water.
  • The exchange of carbon dioxide (CO2) at the surface to oxygen entering the water via the water being agitated is also aeration.

Is Aquarium Aeration Necessary and Why You Might Consider Aerating

  • It is not always necessary to aerate an aquarium however you should read these reasons as to why you might want to consider doing so.
  • Too determine if aeration is necessary consider some of the situations I have already mentioned like a small aquarium surface, lots and lots of live plants in the aquarium, too many fish in the tank are good reasons you might consider aeration.
  • Do your fish seem sluggish? It could be an issue with low levels of oxygen and or high levels of carbon dioxide in the water.

Let’s Look at Expanding on Some of the Above Information

  • If the aquarium has a smaller surface area      

o   The problem with a smaller surface area is that not as much carbon dioxide will leave the tank as quickly as you might need it too. The opposite side of this is not as much oxygen will enter the water when the surface area is small.

o   Now this issue is only if you have a large aquarium gallon and liter wise and a small surface area. For example if the tank is a tall tank whether it is octagon or hexagon shaped. It could even be a square or rectangle.

o   If you have a standard 55 gallon (208 liters) tank or similar then you probably won’t have an oxygen issue as these types of rectangular tanks have very large surface areas which allows for surface agitation. Surface agitation gets the CO2 out of the water and oxygen into the water.

  • If the tank is filled with live plants

o   Now when I say “filled” with live plants I mean “filled” with live plants. If you have a few plants and a large surface area and a modest amount of fish then you might not need to be concerned. If your aquarium has so many plants that it takes you a while to find the fish in the tank then that is “filled”.

o   Live plants in the aquarium will require some oxygen which the plants absorb out of the water. This means that live plants are absorbing oxygen that your fish need as well.


  • If the tank is maxed out for fish. Your fish produce waste and the fish waste produces CO2 (Carbon Dioxide) in the water which means the balance of oxygen and CO2 is flipping the wrong way.

Is Too Much Oxygen Bad for Fish?

  • I have heard some people talk about a bubble disease because there was too much oxygen in an aquarium. Myself personally I have never seen this disease.
  • I don’t know if it is scientifically possible for a tank to have so much oxygen in it that it would cause issues for the fish. I would think that water molecules can only absorb so much before they are topped up.
  • So even though I cannot explain scientifically why there can be too much oxygen or not I am going to throw caution to the wind and say that you do not have to worry about having too much oxygen in your aquarium which would adversely affect the fish. 

Is an Air Pump Necessary for an Aquarium?

  • Not necessarily. If your tank has a large surface area there is an exchange of the CO2 from within the water and the oxygen in the air when the water is agitated. If there is good water flow then you might not need to aerate.
  • Some aquarium filters come with an air tube that sucks in air and feeds the water as it is pumped back in to your tank. If you have one of these filters then you probably don’t need an air pump.

Where Does the Air Pump Go in a Fish Tank?

  • Air pumps usually do not go in a fish tank. They are kept outside beside the tank or below in a cabinet.

How Long Should You Run Air Pump in a Fish Tank?

  • This is really up to the aquarium owner in my opinion. If you need a recommendation I would say run the air pump when someone is around so they can enjoy the beautiful bubbles for no more than about six hours per day.
  • Run the air pump as long as you feel necessary based on the information I have provided in this article.

Do I Need Air Bubbles in My Fish Tank?

  • No you might not need to add air bubbles to your fish tank.
  • However keep in mind that bubbles are great because when they burst at the surface level they agitate the water so the CO2 leaves the water and the oxygen in the air gets absorbed by the water.
  • Are air stones good for fish tanks?
  • There is some benefit from using air stones in a fish tank. I don’t feel they are a necessity considering you can increase the water flow to achieve the transfer of CO2 and oxygen at the surface.
  • Air stones are enjoyable to watch and do provide some benefit so you could say they are good for fish tanks.

agitating surface water of aquarium is important for increasing the oxygen level of the water.

How to Aerate a Fish Tank Without a Pump?

  • Good news! As you can aerate a fish tank without an air pump by running power heads in a way that the water surface is moving enough that it is agitated which will in turn cause the exchange at surface level of CO2 and oxygen. This increases the oxygen level in the water of the aquarium.
  • Keep in mind that if your tank has a smaller surface area and you increase the water flow in the tank that you could potentially make it difficult for the fish to navigate the water as well there might be splashing at the surface causing water to spray out of the tank.


So there you have it. I tried not to jump around too much and provide you with enough common sense information so that you could decide whether or not you should aerate your aquarium.

There are definitely good reasons to add air to an aquarium in order to increase the oxygen levels. Aside from providing a healthy environment in your tank adding air or increasing the water flow is always a joy to watch.

tanks with a lot of live plants can benefit from being aerated.