How To Add Oxygen to Fish Tank 

You’d agree that oxygen is an essential part of your fish’s life; they would simply die without it. So, just the way you need oxygen to breathe and plants need the sun and water to stay alive, that is the same way for your fish.

It is not just about putting them in water; it’s putting them in water with enough oxygen to survive. Your fish uses oxygen by absorbing it through their gills; the oxygen then travels through their gills into their bloodstream.

How To Add Oxygen to Fish Tank 

The oxygen in their tanks should be kept at the average level regardless of fish species, as it is critical for keeping your fish alive. Generally, the amount of oxygen in your tank depends on how high your tank is, how often you pour water into the tank and how many times the process is repeated.

The oxygen level in one fish tank might not be the same as that in another; this is because of something called saturation.

Saturation means the amount of oxygen that the water in your fish tank can hold.

Are you wondering why you need to add oxygen to fish tank? Shouldn’t the water in the fish tank be enough for them? And how to add oxygen to fish tank?

These are very valid questions, and you will get all your answers here.

Why You Need To Add Oxygen to Fish Tank

Basically, you need to add oxygen to your fish tank when you notice the oxygen in your fish tank has reduced. At this point, adding oxygen quickly to your fish tank should be a priority. 

Here are more reasons you should add oxygen to your fish tank. 

  • Your fishes are unlikely to survive with less oxygen.
  • It doesn’t allow other organisms like algae to thrive; these organisms are not beneficial and might harm your fish.
  • It becomes easier for small fish to swim quickly.
  • Less oxygen causes an imbalance in the fish tank ecosystem.
  • Less oxygen prevents some waste from floating.
  • It will preserve live plants in the fish tank.

When You Need to add Oxygen to Your Fish Tank

When You Need to add Oxygen to Your Fish Tank

There really isn’t a red blaring light that tells you when to add oxygen into your fish tank. However, these signs should help you know when you should add oxygen to your fish tank;

  • Your fish is swimming sluggishly. 
  • They swim to the surface of your tank more than usual and appear to be gasping for air.
  • Your fish flap their gills more rapidly to get more oxygen.
  • There are fewer bubbles than usual in your fish tank.
  • Your fish are not eating as much as they used to.

Causes of Low Oxygen in Your Fish Tanks

The following are the likely cause of low oxygen in your fish tank;

1. Too many fish in the tank

Having too many fish in a tank reduces the oxygen in the fish tank. This is, in fact, the primary cause of low oxygen in many fish tanks.

Use a fish tank that is appropriate for the number of fish you have. Do not force them to live in a too-small tank; you will definitely worry about the tank’s oxygen level in days.

2. When the temperature is too high

When the temperature is above the fish’s average loving condition, you can expect the tank to lose oxygen. This is because high water temperatures can’t hold enough oxygen that the fish would need.

You can use a digital thermometer to check your fish tank temperature. The best temperature for your tropical fish falls between 65 to 70°F. In case of overheating, start by removing the fish tank heater and turning off the fish tank light.

You can also place a fan above the tank; the fan would blow a cool breeze that can reduce the temperature. Another suggestion would be to put a pack of ice cubes close to the tank. Monitor the change in the fish tank’s temperature so it doesn’t become extremely low.

3. Stagnant water

Movement in water causes oxygen exchange to happen. If this isn’t happening, it would cause the water in the fish tank to lack oxygen.

Stagnant water forces the oxygen to rise to the tank’s top, meaning there is barely any going to the bottom. A fish tank filter is a good idea as it keeps the water moving by taking water from the bottom and releasing it at the tank’s surface.

In addition to the air filter, you can get air stones or a powerhead. The immediate need here is to prevent the water from being stagnant.

4. You have live plants

This is not a factor that happens all the time. However, the living plant can still cause low oxygen in your fish tank.

The deciding factor here is how much your fish tank is receiving. 

For example, suppose the tank has poor lighting or is sometimes dark. Then, your live plant will consume the oxygen available in the water that they usually get from the light. So, provide your tank with enough light to prevent this from happening.

5. Too much waste

Most fish wastes become so much that they block the filter and allow other organisms like the algae that are not beneficial to the fish to thrive. 

For the waste to be broken down, oxygen has to be used. And the more waste is broken, the more oxygen is used, and the more it reduces. Ensure that you clean your tank regularly to prevent this from happening.

4 Ways That Shows How To Add Oxygen To Fish Tank in An Emergency

4 Ways To Add Oxygen To Your Fish Tank in An Emergency

You might not notice your fishes are in danger from low oxygen, but you might have to think really fast to save them when you do. Here are 4 ways to add oxygen to your fish tank in the case of an emergency.

1. Pour water into your fish tank

Take some clean water from a height and slowly pour the water into your fish tank to do this correctly. It begins to charge the water until the oxygen level becomes balanced again.

2. Change the water

Take 50% of the water in the fish tank out and replace it with fresh, clean water. The new water would have enough oxygen to shoot up your fish tank oxygen level.

3. Battery-powered air pump

A battery-powered air pump does not require electricity to function. This might be a better option if your power supply isn’t consistent. Using this ensures that your fish tank’s oxygen level doesn’t fall when there is no power supply.

4. Try ice cubes

Not many people know this but using ice cubes is an effective way to reduce the temperature of your fish tank. Get a zip lock or any bag you can use to hold it, place it at the side of your fish tank and watch it do the trick.

4 Ways To Permanently Add Oxygen To Your Fish Tank

For a permanent way to add oxygen to your fish tank, the following methods are practical and easy to follow to ensure that you increase the oxygen level in your fish tank.

1. Try an air pump

An air pump is also an effective way to add oxygen to your fish tank permanently. Air passes through the pump and is released from an air stone into the fish tank.

This remains one of the simplest ways to add oxygen to your fish tank. When choosing your air pump, go for brands that have proven to be efficient so you don’t end up with an air pump that is prone to malfunction and make a loud noise. 

2. The spray bar works too

A spray bar works well if you prefer a canister filter. Moreover, it also allows the oxygen to flow to the bottom of the tank.

3. Put a fountain in your tank

Placing a fountain in your tank can increase the amount of oxygen. It pushes the water around and ensures oxygen is well distributed.

4. Try a HOB filter

This filter performs an excellent job if you want to add oxygen to your aquarium. They are easy to use no matter the size of your fish tank. 

How the HOB filter works is simple; it takes water in and returns it to the tank from a height. This helps increase the water’s movement. The water is taken to the bottom of the tank and allows oxygen to circulate well.


Owning a fish tank comes with a lot of responsibility that can’t be avoided. So, monitor the condition of your fish tank regularly, even though it might seem challenging. 

Consider using the information here as it will be of great help and keep your fish alive and healthy. Do more than just read and get informed; share with many you think might need this information.

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