Air pumps are commonly used with aquarium filters, decorations, and many other air-driven devices, but what exactly do they do and how do you know if your fish tank needs one? In this article, we explain when to use an air pump, how to pick the right one, and how to install it in your aquarium.
What is a Fish Tank Air Pump?
An air pump is a mechanical device that sits outside of the fish tank and uses electricity (either from a wall outlet or battery power) to pump air into the aquarium. The air travels from the air pump to the fish tank decoration or device using airline tubing. Once it enters the water, the air creates bubbles, which float to the surface and pop.
The rising bubbles help create movement in the water, as well as surface agitation. Good surface agitation is the key to proper gas exchange in the aquarium, so that excess carbon dioxide (a waste product produced by your fish) is released into the air and new oxygen from the air dissolves into the water for your fish to breathe. If your fish are gasping at the surface, read this article about adding an air pump with a simple air stone to increase oxygen levels in the water.
Does my aquarium need an air pump? Not necessarily. Some types of filters – such as hang-on-back and canister filters – use an electric motor to move water and do not work with an air filter. However, air-driven filtration devices – such as sponge and undergravel filters – use air to move the water and therefore require an air pump. If you’re still unsure, read the instructions to see if your equipment or decoration needs an air pump to run.
Sponge filters use air pumps to provide bubbles that pull water through the sponge and strain out particles floating in the water.
What is an aquarium air pump used for? Air pumps are used in conjunction with many fish tank decorations and devices, such as a:
- Air stone or aquarium bubbler – creates smaller, finer bubbles from the air pump for decreased noise, improved filtration (when used with a filter), or decorative appearance
- Sponge filter, undergravel filter, or corner box filter – uses the rising bubbles to draw in water through the filter and strain out floating particles
- Moving bed filter – uses air to churn the biological filter media and grow beneficial bacteria
- Fish tank decoration – uses bubbles to, for example, open and close a treasure box ornament or mimic a little scuba diver
- Breeder box – increases flow inside the box to prevent stagnant water and improve oxygenation
- Egg tumbler – uses air to direct water flow onto fish or shrimp eggs, gently tumbling them to decrease fungal growth and increase hatch rates
How to Install an Aquarium Air Pump
An air pump is responsible for sucking in air from outside of the fish tank and pumping it into a submerged aquarium apparatus. Therefore, you need a few air pump accessories to guide the air flow in the right direction and at the right pressure. For most beginners, we recommend getting a roll of airline tubing and check valve to get started. The other items are optional, depending on your specific application.
- Airline tubing – directs the air flow from the air pump into the aquarium equipment or ornament
- Check valve – prevents water from leaking out of the fish tank if the air pump turns off or loses power
- Air valve – controls the amount of air flow coming from your air pump into the aquarium
- T splitter – splits one airline into two channels, allowing a single air pump to run two devices
- Gang valve – splits and controls the air flow from a single air pump across four different aquarium devices
- Airline holder – uses a suction cup to hold your airline tubing in place, either inside or outside the fish tank
- Airline connector – connects two pieces of airline tubing together to reach longer distances
This black airline tubing is essential for directing air flow from the air pump into the sponge filter.
Once you have purchased the air pump, aquarium device or decoration, and necessary accessories, follow these basic instructions to install the air pump:
- Place the air pump in its final location outside of the aquarium, and then cut the airline tubing to the proper length so that it is long enough to connect the air pump to the aquarium device inside the aquarium. (Add some extra slack in the airline tubing just in case you need to move the air pump or aquarium apparatus in the future.)
- Connect one end of the airline tubing to the aquarium device and place the device inside the fish tank. Then connect the other end of the airline tubing to the air pump.
- If the air pump is positioned higher than the top of the aquarium, you can skip this step. If the air pump is positioned lower than the top of the aquarium, you need a check valve to prevent water leakage through the airline tubing. Cut the airline tubing somewhere between the sponge filter and the aquarium device, and attach the check valve in between so that the end of the check valve with the flapper (typically looks like a colored or horizontal bar) is facing the air pump. If you install the check valve backwards, no air will flow when you turn on the air pump, so just flip the check valve around.
- Create a drip loop with the power cable of the air pump (to prevent water from entering the wall outlet), and then plug in the air pump. Within a few seconds, you should see bubbles coming from your aquarium device.
Specific instructions for installing your air pump and aquarium device can usually be found in the user manuals, so please consult them for more details.
Can an aquarium air pump be adjusted? If the amount of bubbling in your aquarium is too much or too little, you may want to adjust the air flow. Some air pumps come with an adjustable dial to increase or decrease the flow. If your air pump isn’t adjustable, you can also attach an air valve to control the air flow.
Should I keep my air pump on all night? Generally speaking, you should leave the air pump on all the time to help your fish get good water circulation and plenty of oxygen to breathe. If you are worried about the noise caused by an air pump at night, see the section below for possible remedies.
How to Make an Aquarium Air Pump Quieter
If you bought an air pump from the pet store, most likely it’s a diaphragm air pump, which uses a diaphragm that rapidly vibrates back and forth to suck in air from its surroundings and then push that air into your fish tank. This vibration unfortunately can become quite noisy over time. Try these solutions to make it quieter:
- Place a small towel, block of foam, or other soft material under the air pump to cushion the vibrations.
- Make sure the air pump (and its cushion) is resting on a solid surface that won’t vibrate and amplify the noise.
- If the air pump isn't too heavy, hangit up by the power cable so that the pump isn't touching or vibrating against anything.
- Clean the aquarium device or decor attached to your air pump because it may have gotten clogged from debris or algae growth.
- Consider replacing your air pump with a quieter, smaller one or a model that has an adjustable air flow.
- If the bubbling noise is too loud, try adding an air stone to the aquarium device, if possible. The air stone makes smaller bubbles, which do not make as much noise when they pop at the surface. For example, see our article on how to install an air stone in a sponge filter.
Adding an air stone into a sponge filter or other air-driven filter significantly lessens the bubbling noise and improves the filter’s efficiency.
What Is the Best Aquarium Air Pump?
After testing dozens and dozens of air pumps over the years, we have settled on three units that have superior reliability, low noise level, and reasonable cost. Each pump is best suited for different types of applications, so choose the right one that fits your needs:
Recommended Air Pump forSmall to Large Tanks
Aquarium Co-Op air pump
Our favorite air pump istheAquarium Co-Op air pumpbecause of the included battery backup that can be used in power outages or to transport fish. As with most air pumps, it plugs directly into the wall outlet, but our model also comes with a lithium ion battery that automatically turns onwhen it detects a loss of power. Plus, the Power Save mode further extends the battery life by turning the air on for 15 seconds and off for 15 seconds. This air pumpis great forboth smallandlarge aquariums becauseof theadjustable air flow control.
Recommended Air Pump for Multiple Tanks
Medo LA-45 linear piston air pump
If you have dozens of fish tanks in your care, you may not want to buy an individual air pump for every aquarium. The Medo LA-45 linear piston air pump is what we personally use in our retail fish store and personal fish rooms to run a central air loop system that feeds into each of our fish tanks. Rather than operating on traditional diaphragm technology, it uses pistons (like in a car engine) to pump 47 liters of air per minute, resulting in a quieter, more reliable machine. This pump handles roughly 47 fish tanks (depending on the size of each tank) and can be easily used in conjunction with another linear piston air pump to boost the output of your air loop system as needed.
The reason why many fish keepers prefer to use air pumps is because the technology is proven and dependable, the flow is very gentle, and the total cost is relatively cheap, especially when running many aquariums. If you enjoy articles like this, don’t forget to sign up for our newsletter to receive a weekly email with a summary of our latest blog posts, videos, and products.
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