What is an aquarium air pump?

Some people call it a “bubbler” or a “bubble maker,” while some others have no idea what it is. The equipment makes bubbles you see in the aquariums is a series of connected parts and accessories instead of just one single component.  An aquarium air pump is a crucial component amongst them.

Why do we need air bubbles in the aquariums?

Most people might not even ask this question because we know that fish requires oxygen to survive just like us. When you see fish staying near the water surface, it is very likely that there is a lack of oxygen. The “bubble maker” (air stone) in the aquariums increases the oxygen level in the water. However, many people do not actually understand how the bubbles help increase the oxygen levels. Some people believe fish can use the oxygen from the fine bubbles directly. That is not true because fish breathe through their gills and their gills can only process the dissolved oxygen in the water.

How do the bubbles increase the oxygen level in the water? When I was a beginner in fish keeping, I mistakenly believed that the oxygen in the small bubbles produced by the air stone could more or less be dissolved by the water before they reach the surface.  It is all wrong.

The oxygenation process, in fact, takes place when the bubbles burst at the water surface creating surface movement. The increased water surface movement can promote the gas exchange between the water and the atmosphere. It is the very reason why you may not even need an aquarium air pump if your filter system already creates enough water surface movements in your fish tank. It is also the very reason why it is not required to place the air stone at the bottom of the tank because the distance between the air stone and the water surface does not matter at all. What matters is the bubble bursting at the surface.

An aquarium air pump and its accessories are necessary when you do not have sufficient water surface movement in your aquarium. The more fish, the more oxygen is needed. The higher temperature the aquarium water is at, the more surface water movement is necessary to maintain the same oxygen level in the water.  In most cases, an aquarium air pump is just as a crucial equipment as a fish tank, an aquarium filter, and an aquarium heater.   

Note: There are certain types aquariums, and fish do not need air pump or air stone
1. Planted aquariums with CO2 system
Those who run planted aquariums may use automatic timers to turn the air pump on at the same time the lights are off.  And to turn the air pump off at the same time as the lights are on. It is necessary when you have a CO2 injection system for your plants because the aeration in the fish tank will offset the CO2 system and make it pointless.

2. Fish with labyrinth organ
Labyrinth fish such as Betta (Siamese Fighter Fish) and Gourami can directly breathe air.  An aquarium air pump is not necessary for them.

3. Aquariums run on sponge filters
If you use an air pump to power your sponge filters, there is no need for extra air stones in the same tanks. The bubbles from the sponge filter will achieve the same purpose as the bubbles from the air stones.

4. Aquariums use power filters
Some aquariums use power filters. This type of filter creates a waterfall as the water run through it. If the waterfall is high enough to produce sufficient surface movement, it has achieved the same goal as the bubbles from an air pump.  You may still use an air stone or two as you wish to make sure there is enough oxygen for the fish.  Or just for decoration. Some people like to see bubbles in a fish tank.

What do we need to make bubbles in a fish tank?

To make bubbles in an aquarium, you need
1. An aquarium air pump
2. An air tubing
3. An air stone

To make it more secure for safety reasons, you also need
4. An air check valve to prevent the water from goes back to the air pump in case of a power outage.

To split air tubing and to control the air flow, you can use
5. T(or Y-valve) + Control Valve, or better yet a gang valve.

Which aquarium air pump should I get in my fish tank?

You must get an air pump strong enough to produce enough bubbles for the surface movement. All the aquarium air pumps have the manufacturer recommended tank size rated on their boxes. You may use lower rated air pumps on bigger tanks, or vice versa. Some air pumps can have their air flow adjusted at the pump (Ex: Rena air pumps), or you can adjust the airflow by using a controllable air valve. You may also increase the aeration by use a Y-valve to split one air tubing into two, and connect them to two air stones spread cross the fish tank.

One fact that many first-time buyers of aquarium air pumps might have overlooked is the noise level of the air pump. Some air pumps can be loud and noisy, and they might become louder over time. Choosing an air pump quiet enough is necessary if the noise is an issue for you, it is especially when your aquarium is in the bedroom.

From my personal experience, Rena air pumps are the quieter aquarium air pumps (if you can still find them).  Updated in 2017, Rena might have gone out of business.  It is getting hard to find their products.  Tetra Whisper is a good alternative.  

It seems their higher models are in fact quieter despite the fact they are more powerful. Rena 400 Air Pump has two connectors at the pump, which means you can power two air stones without a Y-valve. Or you can use two Y-valves to split it into four air stones for one or more fish tanks. I keep my air pump inside a closet.  What I used was a very long air tubing to connect it to my air stones in the fish tanks. I can’t hear the noise at all with the closet door closed.

Whatever aquarium air pump you choose a fish tank, make sure you get all the necessary accessories.  

How do I install an aquarium air pump and its accessories in a fish tank?

It is straightforward once you have all the necessary accessories.
1. Choose a safe location for your aquarium air pump
Wherever you decide to put your air pump, you must make sure it is secure and will not fall easily. It must not be installed inside the aquarium (some people actually did it). It requires the air pump to be at a higher level than the fish tank.  So the water will not go back into the air tubing and reach the air pump in case of a power outage. The air pump also must not be directly above the fish tank, because it might fall into the water. It is an electronic device after all.

2. Connect the air tubing to the air pump
All aquarium air pumps have connectors on them. You will immediately know how to connect the air tubing to them once you see it.

3. Install an air check valve
Cut the air tubing with a pair of scissors somewhere near the fish tank.  Add an air check valve to it to prevent the water from getting back into the air pump.

4. Install Y-valve or T-valve
This step might not be necessary if you only plan to use one air stone. Cut the air tubing again near the aquarium and install a Y-valve to it so that you can split one air tubing into two for two air stones.

5. Connect one air stone to each end of the air tubing in the fish tank. You may place the air stone on the substrate, or hang it in the water anywhere you want, as long as it is below the water surface.

6. Plug in power to the air pump and watch the air stones making bubbles in your fish tank.

There is not much to it when you know what you need for setting up the aquarium air pump and its accessories.