Koi Fish Need Oxygen & Helpful Tips To Make Your Fish Healthy

Koi fish are colorful and eye-catching but require extra care and knowledge to preserve. One of the hardest aspects to take care of is the pond’s environment.

We all know that koi fish need oxygen to survive and thrive. That’s why oxygenation is an important factor affecting the creatures’ living environment.

This post will provide you with helpful knowledge related to the koi fish oxygenation topic, so stay tuned to know how to care for your pets better.

How Long Can A Koi Live Without Oxygen?

The length of time that koi fish can live without an adequate oxygen supply may be from a few hours to a few days. But if there’s no dissolved O2 present in your pond, they’ll obviously die within a few minutes.

As long as there is 5-6 ppm (parts per million) of properly dissolved O2 in the pond, your pets should be fine for a few hours at least until you apply one or multiple oxygenation methods that provide the tank with adequate O2.

What Affects Oxygen Levels Of Koi Pond?

Salinity, water movement, water temperature, and the pond’s precise level of O2 are the primary factors that affect the particular amount of time that your swimmers can live without properly dissolved O2.

Tank temperature has a significant impact on the O2 level, yet the degree of aeration and water movement also play a large role.

The general rule is that the warmer the living environment, the less dissolved O2 it can hold. Why? Because water with lower temperatures has denser water molecules packed closely together.

That means it will be harder for O2 molecules to get away from the water. An environment above 29°C can hold about 6-7 ppm of O2, though it depends on various factors.

Meanwhile, environments of 21°C (70°F) can contain 8-9 ppm of O2. We can see that temperature acts as a massive influencer.

Besides, moving water provides the animals with more surface space to swim than water standing still, hence increasing the level of oxygen.

That’s particularly true when the water moves or splashes over an object (for example, a rock), where it can pick up some O2 molecules and bring them into the tank.

The elevation is also an important factor. If you live in an area at a high altitude, the air pressure and the oxygen level in the water will be low since there’s less force crucial for holding/pressing the O2.

Long-Term Oxygenation Methods For Koi Fish

  • Air pumps (air compressors)

Fish breeders should know that an air pump is a necessary tool for providing oxygen in the long term.

This tool uses an in-land device with tubing transporting air to a diffusion plate underwater but in another area of your pond (typically the bottom), helping air bubbles distribute to the entire pond.

Air pumps are powerful, suiting perfectly large-sized ponds or those heavily packed with various fish species which consequently require a more meticulous oxygen supply.

  • Waterfalls & fountains

Water movement can increase O2 supply by captivating air molecules when the water moves and boosting the tank surface.

Waterfalls, fountains, or letting a small stream run into your fish pond are excellent methods to continually provide your pets with O2.

  • Submerged plants

Adding plants to your tank or pond is a wonderful natural method to filter any pollutants and excess nutrients water and provide dissolved oxygen.

Submerged plants also offer habitat and shelter for your creatures and other residents, such as frogs and turtles. Also, they can serve as green food sources for the animals.

  • Decreasing water temperature

An intelligent way to reduce the temperature and maintain a good oxygen level is to shade your pond.

It’s not necessary to shade the entire pond. Instead, you should shade a small portion, usually 40%, so that there is still adequate sunlight for various microorganisms, any amphibians and reptiles present, and plants.

The shaded area will have a lower temperature, so it can contain more O2.

Short-Term Oxygenation Methods For Koi Fish

  • Temporary aeration & water changes

If you intend to transport your fish to quarantine or stock tanks, you should let them be there just until they’ve recovered from illness or injury or are long and firm enough to move to the next location.

Hence, you can mix more O2 into the tank simply by having a small household fan blow on the water or performing periodic water changes while adding an air pump (bubbler).

Check this video out for more koi pond water change and maintenance tips:


  • Oxygen tablets

You can also use oxygen tablets for your pond or temporary tanks. However, this method should be the last resort you think of when it comes to oxygenation.

These tablets contain multiple sodium compounds and hydrogen peroxide that create bubbles while dissolving in water.

The sad news is that those compounds can kill beneficial bacteria, bleach plants and fish eggs, burn gills and fish scales, and adversely affect water quality.

Tips To Maintain Oxygen Sufficiency In A Koi Pond

Besides the most important tactics above, you need to note these tips down to increase the O2 supply further. Though they don’t themselves add more O2 to the pond, they will decrease oxygen depletion.

First, strive to minimize the use of chemicals and fertilizers, like herbicides, as much as possible.

Avoid letting them be near your tanks and pond since they can leak into your aquarium and destroy favorable tank parameters, like pH, which may consequently mess with oxygen concentration.

Since fertilizers will help foster the development of adversely harmful bacteria and algae, they may deplete oxygen.


The stunning appearance of koi fish is a great attraction, but remember that it takes a lot of work to protect your pets and keep them happy and healthy.

Koi fish need oxygen and could survive no more than a few days maximum without a proper, active O2 supply.

We hope our koi oxygenation guide is useful and can help you maintain a thriving koi pond. Thank you for reading!