Air pumps are an electrical system that pushes the air into your aquarium. These are placed outside the aquarium and are connected to an air tube that brings the air into the tank. Air pumps are often used to power filters or air stones.
Air pumps are not needed in all aquariums. In addition to helping filters work, they help aerate and circulate the water inside your tank. This can sometimes be beneficial to the fish as it will help to maintain the oxygen levels inside your aquarium. It can also make the aquarium environment look more natural. Some fish tank filters like sponge filters, Under Gravel Filters (UGV) and Fluidized Bed Filters, have to be paired with an air pump for them to operate.
Just like filters, there are different types of air pumps.
The different types of air pumps vary based on their source of power. Unlike filters, there is not any major difference in the function that the air pumps perform.
These are simple and most commonly used air pumps. They plug into the electrical outlet and the air tube is submerged inside your aquarium. Once it is turned on the pump will start pumping air into the tank continuously.
They are available in different wattages, with the higher ones able to pump air faster. If you have a larger aquarium then you should get an air pump that has a higher wattage. Most air pumps mention the size of the tank they can be used with, so this should eliminate some confusion when choosing the right pump.
Most of these do not have any buttons to control the flow or switch them on/off. Some of the better ones that cost a little more will have a dial to control the amount of air they can pump. They can be easily used with sponge and UGF filters that need an air pump to operate. The drawback to these is that they do not have a backup power source and have to always be plugged in to operate.
Cost – $15 to $50
These run on batteries and do not require an outlet to be plugged into. Since they operate on batteries, the batteries will need to be changed when they get drained. They do not have the power of a plug in pump, so they are not able to pump as much air. Because of this limitation they are not recommended for larger fish tanks. Battery pumps are portable and you can take them with you or move them around if needed. This is great if you have to move your fish in a small tank when taking them to a vet or cleaning the tank.
Battery air pumps are mostly used as a backup air pump when there is a power outage. They are sometimes also used as a secondary pump to improve the aeration inside the tank. A source of irritation with these air pumps is that they are fairly loud.
Cost – $18 to $40
These are hybrid air pumps that run both on electricity and batteries. Plug them into an outlet and they will keep pumping water into the tank. If the power goes out, the unit will switch to batteries to keep the air pump running. This makes sure your aquarium filters will keep working even when your power goes out. It combines the plug-in and battery-powered air pumps into a single unit. This is why they are more expensive.
Cost – $25 to $50
Unlike aquarium filters, there really are not many choices when it comes to air pumps. The most popular aquarium air pump by far is the plug-in air pump. For most aquariums this will work perfectly. The battery only air pump has its uses, but unless you use rechargeable batteries it is not really worth the cost. If you have occasional power outages and just want to know that your aquarium will continue to have good filtration and aeration the battery backup air pumps are a great choice. Most aquariums will be able to go 6-10 hours without a problem even if the power does go out, so for most we just recommend the plug-in air pump.
Something most people think about as an afterthought are air stones. Air stones are porous stones that connect to an air pump and diffuse the air into smaller bubbles.
If you just ran a tube right from your air pump into your aquarium you will get giant bubbles that don’t really do all that much to aerate your aquarium. They also help sponge filters do a better job pulling particles out of the water. Something most people don’t even realize is that the amount of noise their aquarium makes can be cut down with an air stone and having smaller bubbles.
In addition to aerating your aquarium and helping filters work they also circulate the water in your aquarium. It adds oxygen into the water, and the bubbles moving their way up from the bottom of the aquarium push the water upwards. This upwards water motion also helps spread the oxygen throughout your aquarium as the water moves.