What Are The Best Fish Tank Filter Systems?
Having clean and safe water is crucial to caring for an aquarium or pond and ensuring aquatic life thrives. Having the right water filter system is key for this to happen.
With so many types out there, how do you even begin to pick the right one? Let's delve straight into the intricacies of tank filtrations and break down exactly what you need to know to choose the best water filter system for your fish tank or pond.
Why You Can't Skip The Filter
First up, filters aren't just fancy extras. They’re absolutely necessary if you want to keep your fish healthy and happy. Fish waste, uneaten food, and other debris build up fast, making the water toxic.
A filter also removes a lot of contaminants present in water that can be harmful to aquatic life, such as chlorine, limescale, heavy metals, and much more. If you want to control the amount of algae growing in your tank and reduce maintenance requirements, filters can also help.
With that in mind, let’s dive into the types of filters available.
What to Consider
As is often the case, the answer to ‘what is the best..’ is ‘it depends’. There are quite a few factors that could influence what filter system is best for your aquarium or pond:
- Fish tank size or volume of water – larger aquariums will need more powerful systems that can handle higher flow capacity.
- Noise levels – while not essential for the filtration efficiency per se, depending on where your aquarium is located you should think about how noisy the system will be and whether that will be an issue.
- Space available for filter – again, depending on your set up you’ll have to consider where you want to place the filter and the maximum size for the space you have.
- Maintenance requirements – do you have time to perform more extensive maintenance or do you want something really straightforward? Choosing easy to maintain systems is key if you prefer less hands-on maintenance time.
- Type of aquarium and fish species – a freshwater aquarium will have very different requirements from saltwater ones, and same goes for the fish and aquatic plants that you are caring for. Knowing about the specific requirements of your fish and plants will help determine which system is best or you (and them).
Types of Filtration
We can sort filtration into three main types: mechanical, biological and chemical.
Mechanical filtration is straightforward. It grabs onto solid waste and pulls it out of the water so it doesn’t float around forever. Think of it as the vacuum cleaner for your tank, constantly working to keep things tidy. Sediment filters are a good example of mechanical filtration.
Biological filtration is about balance. It uses good bacteria to break down toxic chemicals like ammonia, which your fish definitely don’t need hanging around. Fluidised bed systems primarily use this method of filtration.
Chemical filtration uses chemical reactions to filter out contaminants we cannot see for ourselves. Dechlorinators and HMA filter systems are common examples.
Some systems like aquatic RO systems will use several methods of filtration at different stages, and it’s worth noting that most methods will partially cover more than one method, such as carbon filters which are primarily chemical but can also mechanically trap larger debris.
Internal vs. External Filters
There are internal and external filters, too. Internal filters are convenient. They are usually easy to set up and maintain. But they do take up space inside the tank which is something to consider if you are working with smaller aquariums.
External filters sit outside the tank, often under it. These are more powerful, handling larger tanks with ease. They’re a bit trickier to install, and they cost more, but they’re worth it for bigger setups.
Aquarium Filter Systems Options
UV Sterilisation
UV sterilisation systems are a popular option chosen by many aquarists to limit algae growth and harmful bacteria in fish tanks and ponds.
- Chemical-free: perfect for those who do not wish to use chemical filtration.
- Low maintenance: UV bulbs and quartz sleeves can easily be replaced and only typically need to be replaced once or twice a year.
- Suitable for both freshwater and marine aquariums of various sizes.
Our recommendation: Finerfilters 25W Ultraviolet UV Steriliser System for Water Treatment
HMA Systems
Heavy Metal Axe or HMA systems have exceptional capacities to remove heavy metals from water such as copper, lead or zinc. They are also effective at reducing chlorine and chloramine levels, making them another popular choice of filter system for aquariums.
- Maintain mineral balance: unlike some other systems, beneficial elements are not stripped from water.
- High longevity and filtration capacity: typically last longer than most carbon filters before needing replacement.
- Great for highly contaminated areas or for sensitive species of fish and aquatic plants.
Our recommendation: Finerfilters 3 Stage 10" HMA Heavy Metal Reduction Water Filter System
Dechlorinators
Dechlorinators, as the name suggests, are highly effective for filtering out chlorine and chloramine. Some models are also great at removing heavy metals, making them a versatile choice.
- Emergency filtration: these systems can make water safe for fish within minutes, making them a great choice in situations where you need to filter water quickly
- Cost effective: these systems have high capacity and can rapidly treat large volumes of water.
- Simple to use: dosing instructions are always straightforward, making it suitable for beginner aquarists.
Our recommendation: Finerfilters High Capacity 10" Jumbo Pond Dechlorinator
Reverse Osmosis
Reverse osmosis is one of the most popular filtration methods. Being able to remove up to 99% of contaminants in water means the quality of water is consistent and it makes it much easier to control parameters within water, making it a good choice for those caring for sensitive fish species.
- Reduced long-term costs: set up may be a little more costly than other options, but membrane and filter replacements are fairly inexpensive.
- Great option for outdoor ponds or aquariums that are in direct light.
- Customisable: the remineralisation stage can be tweaked to suit specific biotope needs.
Our recommendation: Finerfilters 3 Stage Compact Reverse Osmosis Unit
Fluidised Bed Systems
Fluidised bed systems primarily use biological filtration and rely on water movement to grow beneficial bacteria.
- Space-efficient design – ideal for high-bioload tanks with limited space available.
- Self-cleaning nature means less frequent cleaning is needed compared to other filters.
- Can easily be scaled up for larger aquariums and water volumes.
Our recommendation: Finerfilters Fluidised Bed Filter with Hosepipe Connections
DI Resin Vessels
DI resin is often used alongside other methods such as reverse osmosis to achieve near 0 TDS (Total Dissolved Solids). DI resin can be used in specific vessels.
- Removes any trace contaminants that may have gone through other methods.
- Most resin have colour changing cues when the media needs to be replaced.
- Cost-effective option for larger systems.
Our recommendation: Mixed Bed DI Resin 25L; 8" x 17" Resin Vessel with 11 Litre capacity
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