How To Add Oxygen To Fish Tank Without Pump? 6 Powerful Alternatives

Like humans, fish need oxygen to survive. Hence, fish owners install an air pump in the tank. But what if you don’t have one or need a quick oxygen supply?

How to add oxygen to a fish tank without a pump? Fish may not require a pump. Yet, make sure that you give them enough oxygen.

This post will discuss some alternatives you can try in your aquarium.

Let’s dig into the details!

How To Add Oxygen To Fish Tank Without Pump?

Without an air pump, you can use numerous techniques to improve aeration and promote oxygenation in your aquarium.

These suggestions are effective even when there is already an air pump.

Introduce live plants

Live tank plants are fantastic oxygenators that also minimize levels of carbon dioxide and nitrate.

Start with live plants for beginners, like Vallisneria, Anubias, and Java Fern, if you’re hesitant to build a planted aquarium.

To increase oxygen levels within the planted tank, you don’t even need to go into full jungle style.

If you add some midground plants, your fish tank will be much more oxygenated.

Remember that you’ll still need to perform your gardening chores even with low-maintenance species. It’s crucial to trim plants and get rid of rotten leaves.

This video will show you more tips about keeping plants in the aquarium:

fish tank

Add live plants to the tank

Install a filter

The best option for aiding oxygenation in a planted aquarium is a powerful filter with various flow rates. You’ll use it as a 2-in-1 system and won’t need to add any more equipment.

In an aquarium, a powerful filter’s input/output water flow may be sufficient to maintain optimal oxygenation.

However, you should think about the kind of fish you intend to keep in that tank.

Fish that like calm waters or are slow swimmers may become overwhelmed due to the strong current.

Keep the fish at different levels.

Overcrowding is a big headache. Yet, the fish can help with water aeration.

Please note that you should never fill your tank more than 85% of the way.

An excellent approach is finding tank mates who can get along but also cover various areas of the tank.

To fill all zones, get a mixture of bottom fish, mid to top, top to bottom dwellers, and a few surface eaters.

As the fish go about their daily activities, they can spread oxygen-rich water across the entire tank. Aeration will improve thanks to fast swimmers.

salt water fish with coral

The fish themselves can help with oxygenation

Improve surface agitation

Breaking the surface pressure will aid in aerating more water as it occurs at the water’s surface. This method also helps facilitate oxygen intake.

There are multiple ways to stir up the water’s surface. We suggest using any filter featuring a pour-in stream from above, such as waterfall filters or spray bars.

The higher you place the agitation device, the deeper the dissolved oxygen can penetrate the tank.

The amount of water that contacts directly with the air often depends on the tank’s dimensions. As the water surface shakes, more of it can get exposed to air, promoting oxygenation.

Use the cup method

Using a cup or a pitcher is one of the simplest ways to oxygenate the water in your tank without an air pump.

Just fill a cup with tank water, lift it all the way, and refill the tank with water.

As the cup descends to the tank, the water will collect oxygen, introducing oxygen immediately into the water. The higher you pour it from, the more oxygen it can pick up.

Additionally, the water will go farther into your tank’s interior as it falls, aerating the water as a result.

To avoid disturbing too much substrate and detritus when adding water to the tank, you may want to put some sort of plate at the tank bottom.

Expand water surface area

If the tank has more surface area, more oxygen will be dissolved in the water. So, choose a bigger and shallower tank if you don’t intend to utilize an air pump.

This method works best for labyrinth fish, like gouramis or bettas. These species breathe at the surface using their labyrinth organ.

When oxygen levels become too low, they usually act in this manner.

water surface area

Larger surface area provides more air

How Long Can Fish Survive Without Oxygen Pump?

Fish can survive for around two days without artificial ventilation since the water already has enough oxygen molecules.

Fish can live without the oxygen pump, but ensure that you provide them with an appropriate amount of oxygen.

Otherwise, they can only live for a few hours by rising to the surface and breathing the surrounding air.

Signs Of Low Oxygen In Aquarium

Act quickly if it’s been less than two days and you’ve seen the following symptoms. They indicate that your aquarium lacks oxygen, and you need to learn how to add oxygen to the fish tank fast.

  • Your fish will start acting less actively. They swim less and eat less.
  • As your fish try to receive more oxygen through their gills, you can notice faster gill motions and sometimes rise to the surface to gasp for oxygen.
  • Your fish will gather near the surface, opening their mouths wide to breathe repeatedly.


You can still oxygenate your fish tank without an air pump with live plants and the cup method. Some tips for expanding the surface area can also help.

Surprisingly, fish can help with aeration. Just try to choose the fish that prefer living in different parts of the tank.

If you follow our guide and have any problems, don’t hesitate to contact us. We will be glad to help. Thank you for reading!