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Home > Goldfish > Do Goldfish Need an Air Pump? 5 Ways to Tell

Do Goldfish Need an Air Pump? 5 Ways to Tell

Nymph goldfish in the water

All aquatic life requires a form of aeration inside of their aquarium. Oxygen is essential in goldfish and they need it to carry out basic bodily functions. An aeration system is important and will provide oxygen to the aquarium. Well-aerated water that is kept fresh and clean is one of the best ways to keep a goldfish healthy. They need as much oxygen as possible inside of the water which is obtained through good surface movement.

Oxygen is also important for the beneficial bacteria growing in the filter media, which turns toxic ammonia into nitrates and helps protect goldfish from harmful waste toxins in the water.


The 5 Signs your Goldfish Requires More Oxygen

  • Gulping at the surface of the water. They are trying to take in as much oxygen as possible at the surface of the water.
  • Rapid gill movement can be a sign that your goldfish is working extra hard to take in enough oxygen.
  • Laying lethargic at the bottom of the aquarium means that your fish is suffocating from the lack of aeration in the tank.
  • If the water is stagnant, there will be no gas exchange taking place and your goldfish requires an aeration system.
  • A goldfish that appears to be yawning constantly is a sign your goldfish cannot take in valuable amounts of oxygen within the water and is gasping below the surface to take in more oxygen. Keep in mind goldfish do not yawn as humans do and it is usually a sign of gill parasites or poor oxygen levels within the water.

The Amount of Oxygen Goldfish Require

To put it simply, goldfish require a lot of oxygen. For this reason, you need to place various aeration systems throughout the tank. They should also not be placed in bowls or small spaces where the surface of the water is significantly smaller than the rest of the aquaria.

Goldfish are large and active fish that will quickly take up oxygen in the water. This is another reason goldfish should have large tanks. The bigger the tank, the more dissolved oxygen is available in the water for the goldfish to take in.

Overcrowding can also cause the goldfish to compete for oxygen. Stocking the goldfish tank correctly is important to ensure each goldfish can breathe properly and take in oxygen with little effort.

goldfish plant
Image By: gunungkawi, Shutterstock

How Temperature Affects Oxygen Levels

Cold water holds more oxygen than warm water does. Since goldfish are temperate water fish, they should be in a tank with a temperature ranging from 17°C to 24°C. Goldfish are used to naturally taking in more oxygen because they originate from cold water.

If the temperature seems to frequently warm to over 25°C, your goldfish will struggle to retain oxygen. Tropical fish are adapted to less oxygen and that is why tropical fish can handle warm water with minimal oxygen issues.

How Goldfish Breathe

Goldfish breathe through their gills that move in synchronization to their mouth. They draw in the oxygen through the gills and expel carbon dioxide. The gill flaps will open and close to let oxygenated water in and this helps your goldfish to breathe effectively in an aquatic environment. Goldfish do not have lungs as mammals do, and their mouth and gills are the primary external body movements to take in oxygen.

goldfish in freshwater
Image By: luckypic, Shutterstock


Types of Aeration for Aquariums

As the years have passed and fish keepers have found new ways to oxygenate an aquarium, various aeration systems are readily available on the market.

  • Some filters come with a built-in spray bar or waterfall system. This encourages surface movement, but it should be paired with an air stone to achieve maximum aeration within the water.
  • An air stone and air pump are a classic way to roughly move the surface of the water with a cascade of bubbles. These are one of the most popular, cheapest, and effective ways of aerating an aquarium.
  • Bubble walls are usually a large strip mimicking the same aspect of an air stone. The bubble wall has holes where the air pump pushes air through to create a wall of bubbles that oxygenates a larger surface area than standard bubblers.
  • Producers have come up with ways to aerate the water while adding a decorative touch to the aquarium. This includes bubbling decorations like a diver, plant, volcano, and other creative decorations that hook up to an air pump.

The Importance of Surface Area

Oxygen enters the water through the surface. This makes it important to have a proportionate aquarium. Goldfish do best in a rectangular aquarium because of the amount of surface area the tank design has to offer.

When you are using an aeration system, the surface movement lets oxygen inside, which then gets used up by the goldfish and is quickly replenished.

If you're new to the world of goldfish keeping or are experienced but love to learn more, we highly recommend you check out the best-selling book, The Truth About Goldfish, on Amazon.The Truth About Goldfish New Edition

From diagnosing illnesses and providing correct treatments to proper nutrition, tank maintenance and water quality advice, this book will help you to ensure your goldfish are happy and to be the best goldfish keeper you can be.

Tall cylindrical tanks are not a good aquarium design for goldfish. The proportion of the surface to the bottom of the aquarium is not ideal for proper gas exchange. Oxygen will rarely reach the bottom of the aquarium and this will cause the goldfish to stay near the surface.

goldfish and guppies in tank
Image By: Tony Stock, Shutterstock


The Function of an Air Pump

Air pumps are usually an electrical box that is plugged into an outlet. The air pump is connected to aquarium grade airline tubing which is then placed inside of a tank and connected to an air stone. When the air pump is switched on, it pumps air at high speeds through the airline tubing and the small porous holes in the air stone. Bubbles will emerge and oxygenate the surface.

Remember to keep the air pump above the water level in case the power goes out and the water flows through the tubing and into the air pump which will break as a result.

Never dry run an air pump as you will quickly burn the motor and it will no longer work. Always have the tubing and air stone connected and submerged in the water when you switch it on.

Image By: hineck_Pixabay



Oxygen is important to goldfish and they need to have constant access to an oxygen supply. Running an aeration system is just as important as a filter and will provide oxygen to keep the aquarium’s micro-organisms and goldfish healthy. All goldfish require an aeration system even if they do not show any symptoms of low oxygen levels. It is the most humane and essential way to give your goldfish some help to breathe properly.

Featured Image Credit: Kateryna Mostova, Shutterstock

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