How To Choose The Right Pump For Your Aquarium

Home aquariums are enjoyable, decorative, and naturally utilitarian. They’re captivating to watch, but they’re also small-scale ecosystems that host living things and work hard to create homeostasis, with or without human intervention.

To sustain and maintain a healthy environment for your pet fish and other coexisting organisms, it’s important to selectively choose the right accessories and equipment to optimize the life going on inside your aquarium.

With modern technology, it’s easy to find quality appliances and effective tools that facilitate aquarium maintenance and meet your needs as an amateur or experienced aquarist.


Why Pumps Are Necessary

When considering overall aquatic equilibrium, air and water pumps are essential equipment for a well-functioning aquarium. Both types work together to support a healthy underwater environment by adequately circulating water and air, and providing filtration.

pumps in aquarium

Pumps are designed based on the fish tank size and type (freshwater or saltwater). Thus, choosing the right kind of pumps depends on a variety of factors.

Purposes of Pumps

When considering a pump, it’s imperative to learn its usage in relation to its make. The two types of pumps according to purpose are the following:

  • Air Pumps

The primary purpose of an aquarium air pump is to force air into the water, generating aesthetically pleasing bubbles. But it also has a functional use, as an air pump helps oxygenate the water, which is healthy for fish and other organisms.

It also increases water circulation so that water from the bottom moves toward the surface and releases carbon dioxide, making space for more oxygen.

  • Water Pumps

The basic function of a water pump is to allow for filtration in the water, which is essential for removing waste and stabilizing nutrient levels.

This kind of pump also circulates the water and creates movement or currents in the water to keep things from stagnating. A good quality water pump helps to keep your fish tank clean and self-sustaining.

Types of Pumps

Pumps also come in types dictated upon the location of its placement. These are the following:

pumps in aquarium

  • Submersible

This version of a water pump operates completely underwater and pulls water through the pump, which is then filtered. A submerged pump operates quietly, is easy to install, and doesn’t require much energy to pump since it primarily works based on water pressure.

One disadvantage, though, is that it uses the aquarium as a cooling agent, which can increase the water temperature above what is optimal.

  • External Or In-line

An in-line pump is installed outside of the water and circulates water in the tank externally through inlet and outlet hoses. Unlike a submersible one, it doesn’t alter the temperature of the tank water. It also has more power, which makes it better for larger volumes of water and bigger fish. By comparison, it’s even easier to maintain and repair when it malfunctions or breaks.

One disadvantage of an external pump is that it’s louder and needs more energy to operate.

There are also two varieties of external pumps to choose from:

In-line pressure set-up: the pump is placed before the canister filtration system.
In-line free-flow set-up: the pump is put in place to work after filtration.

Flow Rates

For air and water pumps, flow rates are measured in liters per minute (L/min). The flow strength depends on how you intend to use the pump. For decorative purposes, you don’t need as much power, and a smaller air pump around 0.5 L/min should be adequate for tanks that are 10 gallons or less in volume.

Larger pumps are generally 6 L/min and are well-suited for larger tanks that hold up to 160 gallons.

Determining Pump Size

To ensure you’re buying the right sized pump, you can use a simple calculation to know which is best for your tank size and type. A good rule of thumb is having a flow rate of five gallons per hour (GPH) for every gallon of water, but this is specific to freshwater aquariums.

Saltwater aquariums require more water flow for proper filtration. The optimal flow rate is six to seven gallons per hour, so you’ll need a bigger, more powerful pump.

Also, a stronger current in the tank water imitates the natural flow of marine life and keeps fish physically and mentally stimulated in an artificial environment. The ripple effect of synthetic currents from pumps helps to evenly distribute nutrition in the water and move waste around before it can build up.

Planted aquariums need the least amount of water flow, although some flow is essential for underwater plant growth and health. Water movement increases the plants’ ability to obtain nutrients and carbon dioxide.

Too much flow, however, can stunt plant growth and cause stress to foliage. A gentle flow created by a low-impact circulation pump is ideal for aquatic plants. Avoid pumps that cause too much surface agitation in the water, which can divert the flow of carbon dioxide away from plant life beneath the water’s surface.

Determining Attachments

You can find multi-purpose pumps with additional equipment attached for more advanced filtration, sterilization, water regulation, and protein skimming abilities. There are some available that are designed to facilitate water changes, specifically with the task of draining and refilling your tank. Just make sure that the pump and its attachments are the right kind and will fit size-wise with your aquarium.

Attachments and accessories for air pumps are great for making them work more effectively and efficiently, such as pipe valves, gang valves, check valves, and airline tubing.


With all the options available to choose from regarding air and water pumps, it’s easy to get confused or overwhelmed. To avoid buying the wrong kind, it’s wise to start with a simple style from a standard, reputable brand.

If you know exactly what you need a pump for, you’ll be able to make a more informed decision based on unique and individual necessity instead of marketing appeal. You can always upgrade to a different kind or add attachments as you see fit. The priority should always be to keep your aquarium running smoothly and make sure your pet fish are happy and healthy.

Keeping a sharp eye on the quality of water and the behavior of your fish is a good way of tracking how well your pump equipment is working, and if it needs to be adjusted.

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