Which pump for a small aquarium?

Pump or filter: what do you need?

The term "aquarium pump" is often used to refer to two different pieces of equipment:

A pump alone circulates the water but does not filter it. An aquarium needs filtration: to trap particles and provide a surface for the bacteria that convert ammonia and nitrites. In a small tank, an internal filter meets both needs in a single compact device.

Circulation pumps can be used as a supplement, for example to prevent areas where water stagnates, or in special setups. For your first small aquarium, start with a good internal filter.

The selection criteria

The aquarium volume

This is the main criterion. Every manufacturer indicates the aquarium volume for which their filter is designed. Calculate the actual volume of your tank (length × width × water height), then take into account the substrate and decor that occupy part of it. Choose a model whose range covers this volume.

Flow rate and its adjustment

In a small volume, a current that is too strong tires the fish and lays the plants flat. An adjustable flow rate, a directional outlet, or a drip bar allows you to adapt the current. Our article on the filtration flow rate for an aquarium details the calculation.

Space requirements

An internal filter occupies part of the aquarium. Check its height and depth, as well as the space available under the lid.

Noise and consumption

A desktop or bedroom aquarium should remain discreet. Product sheets often mention the noise level or consumption: an energy-efficient motor is also often quieter.

Some models suitable for small aquariums

Here are three models we offer, with the characteristics given on their product sheets:

• Sera Fil 60: internal filter presented as quiet and requiring little maintenance, with an energy-efficient motor. 7 W, 380 l/h, 0.9 m discharge height, for aquariums up to 60 liters.
• JBL CristalProfi i80 greenline: modular internal filter for aquariums from 60 to 110 liters, with a consumption of 4 W. Its outlet tube pivots 90°, and it connects to a wide jet nozzle or a drip bar.
• Sera FP pumps: adjustable submersible pumps for filtration, aeration, and circulation, available in several power classes. The product sheet specifies that the smallest models in the range are suitable for nano aquariums.

Special cases

The nano aquarium

In an aquarium of a few dozen liters, every centimeter counts. The smallest filters and pumps are designed for these volumes: the Sera FP pump sheet indicates, for example, that the FP 100 and FP 150 models are suitable for freshwater nano aquariums from 10 to approximately 50 liters. In a nano aquarium, the water degrades quickly: regular maintenance and a very moderate population are essential.

The shrimp aquarium

Baby shrimp are tiny and can be sucked into the filter intake. A fine sponge placed over the water inlet protects them while allowing water to pass. The current must also remain gentle. Our article on setting up a shrimp aquarium details these precautions.

The planted aquarium

In a heavily planted tank, a surface that is too agitated accelerates the loss of CO₂ that the plants need. Direct the outlet to create water movement below the surface, without splashing, while avoiding dead zones where debris accumulates.

And the air pump?

The air pump, or bubbler, does not filter the water. It creates bubbles that agitate the surface and promote gas exchange. In a well-filtered small aquarium whose outlet already ripples the surface, it is not always necessary. It can be useful when the water is warm, when the population is large, or when the filter outlet is submerged. Our article on choosing an air pump for an aquarium helps you decide.

Properly installing the pump

1. Place the filter in a corner, preferably at the back, where it is discreet and circulates the entire tank.
2. Secure it with its suction cups without letting it touch the bottom or decor, to limit vibrations.
3. Direct the water outlet toward the surface or along the glass, for a gentle current that slightly ripples the surface.
4. Check the water level: the water intake must remain submerged, even after evaporation.
5. Plug it in with a drip loop on the cable, so that no drops run down to the outlet.

Our article where to place the pump in an aquarium complements this advice.

Starting a small aquarium

A new filter does not yet contain bacteria. In the first few weeks, ammonia and nitrites can rise. To start safely:

• Run the filter before introducing the fish.
• Add aquarium bacteria, according to the product label.
• Test the water, especially nitrites, before introducing the first fish.
• Introduce a few fish at first, then gradually increase.
• Feed lightly so as not to overload the filter.

Maintaining a small aquarium pump

In a small volume, regular filter maintenance is even more important. Rinse the sponges in aquarium water as soon as the flow rate drops, never in hot tap water. During more complete maintenance, remove the rotor to remove deposits: a dirty rotor makes noise and reduces the flow rate.

Also keep a set of replacement sponges: the day one of them deforms, you will replace it without delay, keeping the other to preserve the bacteria.

Avoid cleaning everything on the same day: alternating filter maintenance and water changes preserves the useful bacteria.

Common mistakes

• Choosing a pump alone without filtration: the water circulates, but it is not filtered.
• Taking a filter that is too powerful without adjustment options: the current becomes difficult for the fish.
• Undersizing the filter to save space: the water degrades quickly.
• Replacing all the sponges at once: you remove most of the bacteria.
• Turning off the filter at night for silence: prefer a quieter model.

Frequently asked questions

What pump for a 60-liter aquarium?

An internal filter designed for this volume, such as the Sera Fil 60, rated for aquariums up to 60 liters, or a model covering a range that includes your actual volume.

Do you need a pump or a filter in a small aquarium?

A filter. It combines the pump and the filter media. A pump alone circulates the water but does not filter it.

Should the filter run at night?

Yes, continuously. The bacteria in the filter need a permanent flow of oxygenated water.

How to reduce the current of a small filter?

Use the flow adjustment if it exists, direct the outlet toward the glass or the surface, or install a drip bar.

How often to clean a small aquarium filter?

As soon as the flow rate drops. Rinse the sponges in aquarium water and avoid cleaning the filter on the day of a large water change.

Do you need an air pump in addition to the filter in a small aquarium?

Not always. If the filter outlet already ripples the surface, gas exchange is often sufficient. A bubbler can be useful when the water is warm or the population is large.

Also read

• What filtration flow rate for an aquarium?
• Where to place the pump in an aquarium?
• Understanding the filtration mechanism in an aquarium