Internal Aquarium Filters

When an Internal Filter Is a Good Choice

Internal filters are useful where a compact, self-contained unit is preferred and there is no external cabinet space. Many models are straightforward to install and keep all hoses and water connections inside the aquarium.

They do occupy swimming or aquascaping space, and flow can be strong near the outlet. Check the physical size and create calmer areas where the livestock needs them.

Compare Flow and Media

A higher litre-per-hour figure does not automatically mean a better filter. Consider the aquarium's actual volume, fish waste, preferred water movement and the volume and type of media the unit can hold. Real-world flow normally decreases as media collects debris.

Most internal filters provide mechanical filtration and a surface for biological activity. Some accept extra or replacement media, but the available space and compatible shapes vary. Check the manual before adding loose media or restricting the intake or outlet.

Intake and Livestock Safety

Make sure the intake cannot trap delicate fish and is appropriate for fry or shrimp. A suitable pre-filter sponge can protect small livestock on compatible models, but it also needs cleaning and may reduce flow.

Position the outlet to circulate water through the aquarium without creating constant excessive current. Surface agitation can support gas exchange, while the exact flow pattern should suit the species and layout.

Cleaning an Internal Aquarium Filter

Switch the filter off and disconnect it from power before removing or opening it. Clean the impeller and housing as directed and rinse reusable mechanical media when debris reduces flow.

Avoid replacing or aggressively washing all established biological media at the same time. When preserving the biofilter, rinse biological media in removed aquarium water or suitable dechlorinated water and follow the manufacturer's maintenance instructions.

Compare Other Filtration Options

Browse external aquarium filters, sponge filters and filter media, or return to the complete aquarium filtration range.

Order online across Australia or contact Aquaholics on the Sunshine Coast for help comparing current internal filter models.

Frequently Asked Questions

What is an internal aquarium filter?

It is a powered filter mounted inside the aquarium. It draws water through media and returns it to the tank, providing filtration and water movement in one unit.

Are internal filters suitable for nano aquariums?

Some compact models are, but check the filter's physical size, minimum operating depth, flow controls and manufacturer tank rating against the aquarium and livestock.

Can an internal filter provide biological filtration?

Yes, when it contains suitable established media with adequate water flow. The amount of biological capacity depends on the filter design and media volume.

How often should I clean an internal filter?

Clean it when debris accumulates or flow decreases, following the manual. The interval varies with stocking, feeding and media area.

Are internal filters safe for shrimp and fry?

They can be when the intake is suitably guarded and flow is appropriate. A compatible pre-filter sponge may help, but it requires regular cleaning.

Is an internal or external filter better?

It depends on the aquarium. Internal filters are compact and self-contained, while external filters usually preserve more in-tank space and may offer greater media capacity.