At Swell UK, we carry a large selection of internal filters perfect for small to medium fish tanks. Filtration is essential for keeping your aquarium running smoothly, removing waste and harmful chemicals from the water and keeping your fish safe. Our selection includes products from leading aquatics brands including Aqua One, Eheim, Juwel, Fluval, and our exclusive Swell range.
Internal Aquarium Filters
Help and advice on shopping for: Internal Aquarium Filters
Why choose an internal filter?
These filters are easy to set up and simple to run, and they're great if you don't have space outside your aquarium for more equipment. An internal filter sits on the edge of your fish tank with the outlet just below the water surface. Water is drawn up into the filter and then taken through filter media which strains it before it is then returned to your tank.
These filters typically take up only a small amount of space in your aquarium, and are often less costly than external filters. With simple installation, these models rarely require extra components aside media replacements, and are best suited for tanks on the smaller side.
If you're looking at filtering a large aquarium, try our external filter range.
Why choose Swell UK?
At Swell UK, we guarantee:
- Low prices: Enjoy the best deals on leading aquatics brands (see T&Cs)
- Fast and reliable UK shipping: With next-day delivery options available
- Extensive range of filters and other aquarium essentials
- Expert Guidance: Need any assistance? Our aquatic specialists are here to advise
Frequently Asked Questions
Which is the best internal aquarium filter?
The best internal filter is one that suits your tank setup best. It's important to consider tank volume, stocking levels, and fish species before choosing a specific model.
The biggest difference between these filters is the different filter media or filtration methods. Different filter media is better suited to different types of waste matter and will allow different sizes of particles to get through. Some filters are solely designed for freshwater or marine aquariums while others can handle both, this is normally indicated in the specifications of each model.
For more help, try our guide that explains which is the best filter for your aquarium.
How do I clean an internal filter?
Most of these filters should be cleaned every 2-4 weeks, depending on water volume and fish load. They can be cleaned easily by rinsing the media in a bucket of old tank water, and cleaning off any debris from the filter housing. Replacement sponges and cartridges are available for most filters for the most effective filtration.
What size internal filter do I need?
This depends on the water volume in your fish tank. We typically recommend choosing a filter that can circulate the volume of the tank at least 4-6 times in an hour.
Which internal aquarium filter is right for my fish tank?
It's key that you check the compatibility of your filter with the rest of your tank. First, you need to ensure that your filter is right for the type of water in your tank, a solely freshwater filter could be very damaging to a marine water tank. You also need to check the amount of water your filter can process as a filter can only take so much water through it. Most filters have a suggested upper and lower limit when it comes to tank size to help you figure out which you need for your tank.