Do Koi Fish Need Air Pump?

No, Koi fish do not necessarily need an air pump. Koi fish are filter-feeders and get the oxygen they need from the water passing through their gills.

If the pond has adequate dissolved oxygen levels, Koi fish will be able to thrive without an air pump.

However, for ideal living conditions, it is best if you install one.

Read on to find out more about whether Koi fish need an air pump.

How Much Oxygen Do Koi Fish Need?

Koi fish need about 8-10 ppm of dissolved oxygen in their water to be healthy.

The amount of dissolved oxygen in the water will vary depending on the temperature, depth, and the number of fish in the pond.

Aeration can help increase the dissolved oxygen levels in the water, which is, of course, highly beneficial for Koi fish.

Additionally, aeration can also circulate the water and distribute heat more evenly throughout the pond, which is beneficial for koi fish.

Also read: Why are Koi Fish so Popular?

What Causes Oxygen Depletion in a Koi Pond or Fish Tank?

There are a few things that can cause oxygen depletion in a koi pond or fish tank.


If there are too many fish in the pond or tank, this can also lead to oxygen depletion since the fish will be competing for oxygen.

Ideally, you should have no more than 1-2 Koi fish per gallon of water.

Algae Growth

Too much algae can also lead to oxygen depletion since the algae will be using up oxygen as it grows.

To prevent this, you should keep the pond or tank clean and free of debris.


The warmer the water, the less dissolved oxygen it can hold.

So, in warm weather, you may need to aerate your koi pond or fish tank more often to make sure the koi have enough oxygen.


Bacteria can also use up oxygen as they decompose matter in the water.

Suffice it to say, you should always be diligent in keeping your Koi pond or fish tank clean.

Signs of Low Oxygen Level in Koi Fish

Your Koi fish will also show signs of low oxygen if you haven’t addressed this issue for a long time.


You will notice your Koi fish has started gulping more frequently. This is due to a lack of dissolved oxygen in the water.

The fish will try to get more oxygen by gulping air at the surface of the water.

Rapid Gill Movement

Because your Koi fish is struggling to breathe, you will see the gills moving rapidly.

This is another sign that the oxygen levels in your fish tank are low.


If your Koi fish are sluggish, it’s a sign that they’re not getting enough oxygen.

The fish will have little energy and will be slow to move, and may even just float around listlessly.

Types of Aeration Systems for Koi Fish Tank

There are two main types of aeration systems in a fish tank: surface aerators and submersible aerators.

Surface aerators are typically used in larger tanks and ponds, while submersible aerators are typically used in smaller tanks.

Surface aerators work by creating a stream of bubbles that rise to the surface of the water. The bubbles help oxygenate the water and also help circulate the water.

On the other hand, submersible aerators work by pumping air into the water.

Both types of aeration systems can be beneficial for koi fish, but submersible aerators are generally more effective at oxygenating the water.

Common Aeration Systems Used in Fish Tanks

Air Stones

Air stones are a type of aeration system that can be used in both small and large tanks. Air stones work by diffusing air into the water, which helps oxygenate and circulate it.

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Air stones are a good option for koi fish tanks because they are relatively inexpensive and easy to use.


Filters are another type of aeration system that can be used in koi fish tanks. Filters work by circulating the water and filtering out debris.

Many people recommend using filters in your Koi fish tanks because they are quite effective in keeping the water clean and clear.

Bubble Walls

A bubble wall is simply a wall that has holes in it that allow bubbles to escape into the water. This provides aeration for the water and helps to keep it oxygenated.

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Bubble walls are very easy to install and they don’t cost a lot. You can find them at most pet stores or online.

If you have a large fish tank, you may want to consider using more than one bubble wall.

Bubbling Decorations

Bubbling decorations serve a dual purpose of aerating your fish tank as well as improving its visual appeal.

Some of the most common bubbling decorations available are divers, volcanoes, and plants.

Can Temperature Affect Oxygen Levels in Koi Fish Tank/Pond?

Yes, the temperature can indeed affect oxygen levels. Warm water holds less oxygen than cooler water.

In warm weather or during a heat wave, it’s important to check the dissolved oxygen levels in your pond more frequently.

If the levels drop too low, the fish will become stressed and may even die.

How to Know Your Fish Tank Has Low Oxygen Levels

There are a few signs that your tank has low oxygen levels.

Surface Water

From the appearance of the surface water, you can get an idea of the oxygen levels in your fish tank.

If the oxygen is low, you won’t see much disturbance on the water surface.

This is mainly because the atmospheric air continuously causes motions and disturbances.

The lack of these indicates not enough air. Consequently, the oxygen levels will be down.


When the water is warmer than usual, it can also be a sign that there isn’t enough dissolved oxygen in the water.

As mentioned before, this is because warm water holds less oxygen than cooler water.

If you notice that the temperature in your fish tank is higher than normal, you should check the oxygen levels right away.

Size of the Aquarium

The size of your aquarium can also affect the oxygen levels. Naturally, a small tank will have less water, which means that there will be less oxygen.

Contrary to this, a larger tank will have more water hence having more oxygen.

How to Choose an Air Pump for a Koi Fish Tank

When choosing an air pump for a koi fish tank, it is important to consider the size of the tank, the number of fish in the tank, and the dissolved oxygen levels in the water.

A larger tank will require a more powerful air pump than a smaller tank.

If the dissolved oxygen levels in the water are low, it may be necessary to use a more powerful air pump to increase the oxygen levels in the water.

Additionally, it is important to choose an air pump that is durable and can withstand the elements, as it will be exposed to the water.

Do Koi Fish in a Pond Need an Air Pump?

Similar to an aquarium, Koi fish in a pond may need an air pump to help oxygenate the water.

Koi fish are very sensitive to changes in dissolved oxygen levels, and an air pump will keep the oxygen levels stable.

How to Increase Oxygen Levels in a Koi Pond

If your Koi pond has less oxygen than required, you can take several measures to increase the oxygen levels.

Aquatic Plants

Having aquatic plants in your pond can be beneficial in several ways.

Not only do they look aesthetically pleasing, but they also increase the dissolved oxygen levels in the water.

Plants produce oxygen as a by-product of photosynthesis, and this oxygen is released into the water.

Changing the Water

If you have a koi pond, it’s important to change the water on a regular basis.

This will keep the water clean and clear and will also help increase the dissolved oxygen levels in the water.

If the Koi pond has a lot of waste, it will decrease the amount of dissolved oxygen in the water.

By changing the water on a regular basis, you can remove the waste and consequently, the water gets more oxygenated.

Air Filter

Installing an air filter can be useful if you want to increase the oxygen levels in a koi pond.

The air filter will remove the waste and debris from the water, which will increase the dissolved oxygen levels in the water.

How Long Can Koi Fish Survive Without an Air Pump?

Koi fish can survive without an air pump, provided that the pond or the fish tank is in ideal condition.

If they are not, your Koi fish will start experiencing stress and may become sick.

It’s important to have an air pump in a koi fish pond so that the fish can have a constant supply of oxygen.

Can a Koi Pond or Tank Get Aerated Too Much?

Yes, a Koi pond or tank can get aerated too much. If the oxygen levels in the water are too high, it can be harmful to the gills.

The fish may experience stress and may start to gasp for air due to the increased pressure.

It’s important to maintain dissolved oxygen levels within a certain range so that the fish can live healthy and happy lives.


It is best to install an air pump in your Koi pond or tank.

Even though Koi fish can survive without it, having an air pump just makes it much easier for you as well as them.

Koi fish are quite low-maintenance and they make for excellent pets in your fish tank or pond.

Just make sure that wherever they are, oxygen levels are regularly maintained.

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