Do Canister Filters Oxygenate The Water? What is The Science Behind it? Protection Status

But can canister filters actually increase the oxygen in the tank water? While the device doesn’t influence it directly, you can never deny its secondary contribution to the process.

If you ask about one thing that you would die without, the most common answer would be air, or more specifically speaking, oxygen. Almost all living creatures need oxygen to survive, and the same goes for aquarium fish. But, do canister filters oxygenate the water? The answer is pretty simple, but you have to understand the science behind it as well. 

While most people don’t think about this issue that much, the dissolved oxygen in your aquarium filter is nevertheless very significant. Your pet fish need oxygen for breathing, the plants need it at night, and the beneficial bacteria use oxygen to oxygenate or break down waste. Every living thing that dies or decays inside a fish tank consumes oxygen.

It could be anything like dead or unhealthy plants, decayed live sand or live rock, fish waste, etc. Organic materials, carbs, and proteins can cause low oxygen levels in the aquarium.

Do Canister Filters Oxygenate The Water?

You can find several types of filtration systems available to clean aquarium water. Undergravel filter, HOB filter, sponge filter, trickle filter, internal filter, etc. are fit for small to medium-sized tanks.

However, if you have a large fish tank that contains 20-30 gallons of water or more, a canister filter would be better for you.

But can canister filters actually increase the oxygen in the tank water? While the device doesn’t influence it directly, you can never deny its secondary contribution to the process. Surface agitation boosts the oxygen dissolve rate in the water by promoting gas exchange.

If your canister filter’s return pipe is positioned downward while directed toward the surface, it will create water movement or agitation. And the more surface agitation, the more dissolved oxygen in the tank water. The canister filtration process is also unique for its high flow rate and multiple filtration system.

You can apply mechanical filtration, biological filtration, and chemical filtration with this one filter. The canister filter output nozzle, input, and pump are the basics of the construction. The filter material is different for each type of filtration.

The biological filter media is known as the beneficial bacteria, whereas the activated carbon and sponge are known as chemical and mechanical filtration media. 

What Are Aeration And Oxygenation?


Aeration is a system that uses an air compressor to spread diffused oxygen on the fish tank floor. It will create water movement upwards, bringing cleaner, colder, oxygen-enriched water to the aquarium fish. This process not only averts harmful algal blooms but also improves the water condition emerging from lice skirts/ tarps. It also helps manage the temperature fluctuation of water


While oxygenation is pretty similar to the Aeration method, it utilizes an oxygen generator to dispense diffused oxygen into the fish tank. This system is helpful if the aquarium water has a low oxygen level or when dissolved oxygen is dropped to the lowest point, causing your pet fish to starve and die gradually.

Directly adding excessive oxygen into the water can quickly boost the fish’s health, also stimulating their growth and feeding.

What Are The Differences Between Aeration And Oxygenation? 

The main difference between Aeration and oxygenation is how the process works.

  • While the former needs an air pump, the latter one requires an oxygen generator to distribute the oxygen throughout.
  • The speed of both systems is also different, as the oxygenation takes a quicker effect when compared with the Aeration.
  • Oxygenation is very handy if you are looking for ways to improve the water condition for your fish. But the Aeration system aids you to maintain the temperature and prevent toxic seaweed growth.

Principles Of Oxygen

Just like any animal, fish also needs oxygen to breathe and release carbon dioxide. Hence, your aquarium water needs a specific amount of dissolved oxygen to let the tank inhabitants have a healthy life.  A low oxygen level means your fish tank is in danger, and you have to oxygenate it quickly. Oxygen enters the aquarium water via gas exchange in 2 ways:

  • Surface agitation
  • Plant photosynthesis

The percentage of saturated oxygen in the tank water depends on the salinity level and the water temperature. An increased salinity and water temperature mean the oxygen saturation will be on the lower side.

How To Increase Dissolved Oxygen In Water?

A drop in dissolved oxygen can mean your fish tank is suffering from many dangers. We know how oxygen can enter the water using air and photosynthesis. You can also increase the oxygen levels by adding plants to the fish tank. It will expose the water to pure oxygen. However, you have to be careful as this method can cause supersaturation or excessive oxygen levels than the natural one. 

Method 1: Splash Type Aerator

Use a spray or movable splash-type aerator in your tank water. According to IFA, a motor pump or a mobile tractor can be employed for urgent Aeration for ponds. You should apply it when fish exhibit symptoms of oxygen forfeiture or test shows low oxygen levels. These devices can help to quickly increase the dissolved oxygen in 3-20 acre ponds.

Method 2: Steady Diffuser

Install and operate a steady diffuser method, slow-running paddle wheel and fan, airlift pump suggested by IFAS. These regulated mechanisms can unsettle and blend water on a roster and stabilize the oxygen level to a suitable range. It can be the wave and wind action or blending of less oxygenated water and higher oxygenated water levels. 

Method 3: Air Pump

Install an air pump attached to an air stone, and run it for your aquarium. Anything that encourages water flow is perfect for agitating the water surface of your aquarium. It can be an aquarium bubbler, HOB filter, Powerhead, Wavemaker, Spray bar, Lily pipe, etc.

These machines can cause turbulence in the surface water, which increases the gas exchange between water and air. Similar to adjustable pond aerators, they can circulate dissolved oxygen evenly by mixing the water. Aquarium filters frequently agitate the water and also endorse water oxygenation.

Method 4: Live Plants

Add rooted plants to the aquarium water to stimulate photosynthesis. Photosynthesis occurs under suitable lighting conditions, which will also add dissolved oxygen to the fish tank water.

Biofloc Aeration Calculation

Biofloc technology is known as the blue revolution of aquaculture. This system uses aquatic microorganisms to maintain the water quality, increasing the nutritious value and fending off the pathogen. Here, due to the interlinkage between the physical substrate, organic matter, and a wide range of microorganisms, a rich lipid-protein food source (biofloc) is produced in the pond water.

In case of low oxygen levels, you can use several types of aeration and gas exchange systems in a biofloc. The amount of Aeration needed in each bio floc depends on diverse factors like the density, feeding rate, dissolved oxygen in the pond water, etc. On average, a biofloc system may require Aeration from 6.2-12 HP/m3.

How To Calculate Oxygen Level In A Fish Tank?

Aquarists can use the two most common instruments to calculate the dissolved oxygen in aquarium water.

1. Dissolved Oxygen Test Kit

This one is the most economical out of the two. If you have ever sampled the pH level of your fish tank, you would know about colorimetric tests. The aquarium test is pretty similar to that one. Just add the drops to your aquarium water sample and compare the color tone with the chart. It will help you to specify the dissolved oxygen volume in the aquarium.

2. Dissolved Oxygen Probe/Meter

If you have enough budget to spare, the dissolved oxygen probe can accurately measure your fish tank in mere seconds. Just put the probe inside your aquarium, and check the LCD screen to see the oxygen amount in the tank water.

This device is definitely more precise than a test kit, but you have to supervise it continuously to ensure an accurate result. Remember to replace the battery and calibrate the meter regularly. For the most exact measure possible, there is nothing better than a dissolved oxygen meter.

Frequently Asked Questions [FAQ]:

Final Words:

So, if you think you have nothing to contribute to the betterment of your fish tank, you can never be more wrong! Because every aquarium needs proper maintenance from its filter to the tank water. Even your goldfish tank is no exception! To provide your aquarium fish with a healthy environment, you need to do things carefully.

If you are a new aquarist and just started to learn about keeping fish, you are just in the perfect place to start! In this write-up about ‘Do Canister Filters Oxygenate The Water?’ we have tried to accumulate all the necessary information you need.

We hope these help!

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This site does not constitute pet medical advice, please consult a licensed veterinarian in your area for pet medical advice.

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