An aquarium filter removes physical and soluble waste, maintains water quality, and creates a healthy environment for aquatic life.
But which type of aquarium filter would best suit your needs? Don’t worry, we’ve got you covered!
In this guide, we’ll explore various types of filters and their functions to help you make an informed decision.
So sit back, relax, and let us guide you through the world of aquarium filters.
Why Should You Use an Aquarium Filter?
Aquarium filters perform mechanical, biological, and chemical filtration which are essential to keep the water clean and safe for your fish.
A well-functioning filter helps promote the nitrogen cycle by providing a medium for beneficial bacteria growth.
These bacteria convert harmful ammonia into less toxic compounds that are further broken down and removed from the tank.
In addition to promoting the nitrogen cycle, aquarium filters also help remove debris and waste from the water.
This not only keeps your tank clean but also prevents the buildup of harmful substances that can lead to poor water quality or even disease outbreaks among your fish.
Furthermore, filters aerate the water by generating water flow and bubbles.
These bubbles create gas exchange at the water’s surface by expelling carbon dioxide (CO2) out of the tank water and taking in oxygen.
The oxygen provided by these bubbles is vital for your fish’s survival as they need adequate oxygen levels to thrive.
Simply put, investing in a suitable filter is key to maintaining optimal conditions within your aquarium.
3 Types of Filtration in Aquariums
The three types of aquarium filtration are:
- Biological, and
Each type plays a crucial role in keeping your aquarium environment clean and balanced for your fish and plants.
The aquarium filter that you choose should be able to perform all of these three filtrations.
However, some filters only perform only one of these filtration, some two, while others perform all three.
So you can use multiple filters to make sure your aquarium water goes through all three filtration.
Let’s understand each of these filtration now.
1. Mechanical Filtration
Mechanical filtration is the process through which solid wastes and debris is removed from the aquarium water by passing it through materials like synthetic foam or nylon fiber floss.
These filter mediums capture small particles, ensuring that dirt and other undesirable materials are removed from your aquarium.
Over time, beneficial bacteria colonize the surface area of these filter mediums, allowing them to perform biological filtration as well.
When shopping for a mechanical filter, consider options such as canister filters, power filters, or corner filters. Top brands like Penguin, Ehime, and Whisper offer high-quality filters that cater to various tank sizes.
Choose a filter with a Gallons Per Hour (GPH) rating suitable for your aquarium size.
Ideally, your filter should cycle your tank’s water volume at least eight times per hour.
For tanks larger than 10 gallons, using multiple filters or combining different types of filtration systems is a smart choice.
This not only provides extra cleaning power but also serves as a backup in case one system fails.
2. Biological Filtration
Biological filtration is the process in which a surface is provided for beneficial bacteria to grow so that they can convert harmful ammonia from fish waste and food debris into less toxic nitrites, and then further into nitrates.
This incredible process, known as detoxification or the nitrogen cycle, is essential in keeping your aquarium water clean and safe for your fish.
Biological filters have filter media that serves as the perfect nesting place for these bacteria to multiply and thrive.
When choosing an aquarium filter with biological filtration capabilities, pay attention to the surface area of the filter media: a larger total surface area means more room for beneficial bacteria colonies to grow.
Also, look for filters with modular design – they allow you to replace parts of the filter media without losing all of the precious beneficial bacterial colonies.
For example, power filters with biowheels are better than those with only compact floss and carbon pads because biowheels help retain beneficial bacteria even when you’re replacing the pads.
Always follow the filter manufacturer’s instructions regarding which parts need to be replaced and when so you can keep your aquatic environment healthy.
3. Chemical Filtration
Chemical filtration is the process in which activated filter media like zeolite or charcoal is used to absorb dissolved minerals and harmful chemicals from aquarium water.
As water passes over these filter media, they hold onto the dissolved minerals, impurities, and other potentially harmful chemicals.
You’ll find such filter medium in various types of filters such as corner filters, undergravel filters, canister filters, etc.
Make sure to follow the manufacturer’s instructions to know when to replace the filter medium – typically once a month should suffice.
By regularly maintaining your filter and replacing the activated media when necessary, you’ll ensure that your aquarium remains a safe haven for all its inhabitants.
9 Types of Aquarium Filters
As you start looking for an aquarium filter, you’ll encounter a wide range of options. However, all aquarium filters can be categorized into nine basic types.
The 9 types of aquarium filters are:
- Power Filters,
- Canister Filters,
- Undergravel Filters,
- Sponge Filters,
- Corner Filters,
- Fluidized Bed Filters,
- Diatom Filters,
- Wet/Dry Filters, and
- Pond Filters.
Each type has its unique characteristics and benefits to consider for specific aquarium setups.
Let’s take a look at each of these filter types now.
1. Power Filters (Hang-on-back Filters)
Power filters, also known as Hang-on-back (HOB) filters, perform mechanical, biological, and chemical filtration.
Power filters are easy to install and maintain, as they hang on the outside of your aquarium.
They come in various sizes to accommodate different tank capacities and are powered by an internal motor, eliminating the need for a separate pump.
These filters have removable fiber-coated filter pads containing charcoal on the inside.
To operate a power filter, simply hang it on the back of your aquarium with its intake tube submerged in the tank water.
As water is drawn through the intake tube, it passes over the filter pads and media which house beneficial bacteria colonies that provide biological filtration.
The charcoal within the pads acts as a chemical filter while the fibers catch debris before it can clog up the filter media.
For best results, rinse the fiber pads with dechlorinated water during regular cleaning sessions and replace them monthly to maintain fresh charcoal levels.
Keep in mind that replacing pads may temporarily disrupt established bacterial colonies.
However, there should be enough remaining bacteria in other parts of your aquarium ecosystem to quickly repopulate these helpful organisms.
Some power filters also come with biowheels – an excellent addition that supports long-lasting bacterial colonies even when changing internal pads.
These power filters with biowheels are highly recommended for maintaining a pristine aquarium environment.
2. Canister Filters
Canister filters provide excellent biological, chemical, and mechanical filtration by utilizing several media compartments that house sponges or foam blocks, carbon (charcoal), and ceramic media.
These filters are capable of turning over several hundred gallons of aquarium water per hour.
This makes them an ideal choice for larger aquarium systems where maintaining pristine water conditions is crucial.
The adjustable output also allows you to direct water flow exactly where you want it in your tank.
However, canister filters do have some downsides.
They tend to be bulky and large in size. This means you need a dedicated space to hide them away from view – usually within the aquarium cabinet or behind the stand.
Canister filters are also more expensive compared to other filters and aren’t easy to set up.
That being said, the long-term benefits of having a reliable canister filter far outweigh these drawbacks.
Many models come with added features like connections for ultraviolet sterilizers, inline heaters, or chiller units which further enhance their value.
3. Undergravel Filters
Undergravel aquarium filters consist of a perforated plate (called a filter plate) placed under the substrate (gravel) at the bottom of the aquarium.
The primary function of these filters is to promote beneficial bacteria growth, which helps break down waste products and keep the water clean.
Here’s how an undergravel filter works:
- Water circulation: Lift tubes that rise from the filter pull the aquarium water down. This creates a flow of water through the gravel and filter plates, which pulls down the debris and waste into the gravel and filter plate.
- Mechanical filtration: As water is drawn through the gravel and filter plate, it traps solid particles like uneaten food and fish waste. The debris collected on the gravel should be vacuumed at regular intervals.
- Biological filtration: Beneficial bacteria colonize the surface area provided by the gravel and filter plate. These bacteria convert harmful ammonia and nitrite (produced by fish waste and uneaten food) into less toxic nitrate, which can be removed through regular water changes.
While undergravel filters can be effective for maintaining water quality, they may not be suitable for all aquarium types.
Some drawbacks of undergravel filters are:
- Inefficient filtration if big rocks or decorations are kept in the aquarium that covers a large area of the substrate and filter plate.
- Difficult to clean the filter without disturbing the substrate.
- This filter gets clogged frequently if the accumulated debris is not vacuumed at regular intervals.
- Undergravel filters are getting obsolete because of the availability of better filters nowadays.
Powerhead for Undergravel Filters
Powerheads enhance your undergravel filter’s efficiency by controlling the water flow and circulation in your tank.
These electric motor-driven pumps can be inserted on top of the uplift tubes of an undergravel filter to improve water movement.
They have adjustable valves to allow you to regulate the water flow speed and force, making it easy to customize the environment for your aquarium’s inhabitants.
Some models even come with internal filter pads for added filtration benefits.
Powerheads also allow you to direct water flow precisely where you need it within your aquarium.
4. Sponge Filters
Sponge filters perform both biological and mechanical filtration, making them an excellent choice for quarantine and hospital tanks.
Since they don’t have any chemical filtration, they don’t interfere with any medications you might be using in these tanks.
They’re also perfect for fry tanks or aquariums with small fish because there’s no danger of the little ones getting sucked up into the filter unit.
However, sponge filters do have some drawbacks.
For one, they only perform a limited amount of mechanical filtration and are primarily focused on biological filtration.
This makes them less suitable for use in large tanks where robust filtration is needed.
Sponge filters are also somewhat unsightly because they take up space inside the aquarium itself.
5. Corner Filters (Submersible Filters)
Corner filters, also known as Submersible filters, mainly perform mechanical filtration; and biological and chemical filtration to some extent.
Once only suitable for small aquariums, corner filters now offer more advanced features and improved performance.
Modern corner filters are quieter and equipped with swiveling spouts to change the water flow direction.
They also have water flow adjusters to control the power of the water flow.
Some even include a clogging indicator that shows when the filter media needs maintenance.
Although they’re not as powerful as other types of aquarium filters, their compact design and flexibility make them an attractive option for many aquarists.
Despite these advancements, corner filters do have some drawbacks.
For one, they take up space inside your tank and can be difficult to conceal without the proper placement of plants and decorations.
Moreover, while newer models can be hung vertically or horizontally on glass walls, they often look unsightly.
6. Fluidized Bed Filters (Suspended Particulate Filter)
A fluidized bed filter, also known as the suspended particulate filter, is one of the best biological filters on the market.
Fluidized bed filters use sand, silica, or plastic as a filter medium that provides an enormous surface area for beneficial bacteria to grow and multiply.
These bacteria are essential for breaking down harmful substances in your aquarium water like ammonia and nitrite.
This type of filter also improves oxygenation in your fish tank since the sand is continuously tumbled by water at high speed, creating a fluidized bed where water easily transfers between sand grains and bacterial colonies.
One thing to keep in mind when considering a fluidized bed filter is that it mainly focuses on biological filtration.
To maintain a balanced filtration system in your aquarium, you’ll also need mechanical and chemical filters working alongside it.
Fluidized bed filters are especially great for planted tanks because they don’t remove as much CO2 from the water as other types of filters do.
However, make sure to monitor the sand bed so that it doesn’t become stagnant during power outages.
7. Diatom Filters
Diatom filters are a fantastic choice for keeping your tank’s water crystal clear and reducing diseases.
These filters use diatomaceous earth, which is known for its ability to capture even the smallest of dirt particles.
This results in extremely clean water that helps lower the risk of diseases such as fin rot, velvet, ich, and other issues caused by microorganisms.
You can either hang this filter on your aquarium or place it on the floor next to it.
While diatom filters are more expensive than other options on the market, their effectiveness in maintaining pristine water conditions makes them well worth the investment.
8. Wet/Dry Filters
Wet/dry filters are especially effective in larger tanks because they use a combination of water and air to provide excellent biological and mechanical filtration.
Waste is first removed from the water as it passes through an initial filter. Then, a filtering chamber aerates the water before passing it through another filter.
Keep in mind that wet/dry filters need more maintenance than some other types since the media must be replaced regularly to prevent waste buildup.
While wet/dry filters are great at handling biological and mechanical filtration, they don’t address the chemical filtration needs of your aquarium.
So you’ll need to use another filter to handle chemical filtration.
Moreover, wet/dry filters have a higher rate of evaporation compared to other types of filters.
9. Pond Filters
Pond filters are designed to handle the large volume of water that ponds typically hold.
These filters are basically canister filters in a box.
Some models can be placed directly in the pond while others can be kept on dry land.
Whether you have a full-scale backyard pond or a compact barrel setup, investing in an efficient pond filter is crucial to keep your aquatic environment thriving.
Can You Use Live Plants Instead of Aquarium Filters?
Live plants not only add beauty and interest to your tank but also serve as natural filters that can complement other filtration systems.
By absorbing harmful substances like ammonia, nitrates, and CO2 from the water, plants help maintain a clean environment for your fish.
They also release oxygen back into the water through the process of photosynthesis.
However, be sure that your aquarium has ample lighting to support this process during the day.
Live plants also provide hiding places and breeding grounds for various species of fish.
Frequently Asked Questions
Are External Aquarium Filters Noisy?
Depending on the make and model of the external aquarium filter, it may produce some noise. However, modern external filters don’t make loud, disturbing noises if set up correctly and cleaned regularly. Well-maintained external aquarium filters will only make an electric hum and a trickling sound.
Are Aquarium Filters Waterproof?
Internal aquarium filters are waterproof as they are designed to submerge in the water. For efficient functioning, all components like the valve, tubing, strainer, etc., are assembled to avoid leakages. However, the same is not true for external aquarium filters as they don’t operate underwater.