7 Aquarium Filter Types You Should Know 3

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Aquarium FIlter Type

There are many types of aquarium filters on the market today. Each one has a designated design for one’s preference.

There are some basics that we need to learn about first such as the size of the aquarium versus the filter size and type along with the three types of filtration that occur in an aquarium.

The three types are mechanical, chemical, and biological filtration.

  • Mechanical filtration is where water is forced through filter media which is designed to catch particles suspended in the water in your aquarium.
  • Chemical filtration occurs when toxic chemicals pass through a resin or media. Some chemical filtration products target specific excessive nutrients or chemicals from the aquarium.
  • Biological filtration is the breakdown of different bacteria. This is called the nitrogen cycle where waste products, food, and fungi are broken down and create ammonia. Ammonia is toxic to the aquariums inhabitants. If there is sufficient space for the beneficial bacteria to grow, your nitrogen cycle will work properly. A biological filter is designated by the amount of space made for the bacteria to grow on.

Now that you know the three types of filtration in an aquatic ecosystem, let’s take a look at the different types of aquarium filters.

Aquarium Filter Types

Sponge/Air Driven Filter

The most basic setup filters that do not do much in the way of mechanical, chemical or biological filtration is the Sponge/air filter. These are made mostly for breeding, fry (baby fish) nursery tanks, hospital tanks and aquariums with small fish or invertebrates.

A sponge filter is powered by an air pump where water is forced to pull through the sponge-like material. The sponge is capable of producing biological and mechanical filtration because beneficial bacteria live on the sponge.

You then use aquarium water to clean the sponge to be careful not to kill the beneficial bacteria.

These can vary in price from $5.00 to $40.00.

Recommended - Sponge Filter

Hang On Back/Power Filters

The most common style filters for hobbyists are the hang on back style filter. The reason they are common is because they provide excellent mechanical, chemical and biological filtration.

They hang over the back (or side) of your aquarium and suck water up through their siphon tube.

The mechanical filtration comes from water passing through a filter pad or floss, next chemical filtration occurs from water flowing through carbon which removes toxins or chemicals from the water.

Lastly biological filtration happens inside the filter cartridge. A large number of beneficial bacteria form within the filter cartridge and this is what causes the biological filtration and is limited to the amount of oxygen within the aquarium.

Most new systems have biowheels or biological filter pads. Biowheels are wheels that have a biological filter on them and water passes over them creating a great biological filter.

These can vary in price from $10.00 to $150.00.

Canister Filters

Canister filters are among the popular styles of filters used by hobbyists. These are especially great for aquariums 40 gallons or larger.

Canister filters provide excellent mechanical, chemical and biological filtration due to their size which is significantly larger than most hang on back filters.

These have a siphon tube and flexible pipe work going to the filter and then a pipe back up and into the tank with a return “water bar” that spreads the water outflow through a long bar.

Canister filters are great for cichlid, saltwater or planted aquariums.

Canister filters are pressurized which makes mechanical filtration even better by forcing the water through fine material that can trap smaller particles.

Chemical filtration is done the same way and thus makes it a better chemical filter.

The biological filtration is based on oxygen present in the water going through it. Since there is no air to water contact, biological filtration is not as sufficient in these types of filters.

These filters can range in price from $90.00 to $500.00.

Recommended - Canister Filter

Undergravel Filters

The filters are placed under the gravel and pull the water through the gravel/substrate and up tubes called uplift tubes.

There are two ways you can get water to come up these tubes. That is by an airstone and air pump or a power head that fits onto the top of the uplift tubes and pumps the water across the top of the aquarium.

Mechanical filtration occurs as water passes through the gravel but the downside is that biological filtration is limited from the water passing through the substrate.

Unfortunately chemical filtration does not happen with an under gravel filter. Also make sure you agitate your substrate and clean it or there will be detritus buildups and this will cause high levels of hydrogen sulfide.

These range in price from $8.00 to $60.00.

Recommended - Undergravel Filter

Internal Filters

Internal filters are compact which make them great for small and nano aquariums.

Most people use these in aquariums under 20 gallons as they use suction cups and stick to the side of the aquarium glass.

Most hobbyists place these at the bottom of their aquarium so dirt has no time to settle before getting sucked up into the filter.

Some internal filters also require an air pump and airline connected to it to produce the water movement up through the filter. The air bubbles then dissipate to the top of the surface making good mechanical, chemical and biological filtration.

The price of this style filter ranges from $8.00 to $30.00.

Wet/Dry or Trickle Filters

Wet/Dry filters are not as common as the previous filters we have discussed but quite a few hobbyists use them especially in the saltwater side of the hobby.

These excel in the biological part of filtration due to part of the filter media is exposed to aquarium water and a significant amount to air. Being exposed to both air and water creates a large colony of beneficial bacteria to grow and process waste products.

Setting up this system requires a lot of work including getting plumbed directly to you aquarium with a sump or reservoir to hold auxiliary water and water to run the pump.

Chemical filtration occurs from placing chemical media in the filter and the water flows through it.

Mechanical filtration is limited as water has to pass through large-pored sponges so the water flow is not restricted like other forms of mechanical filtration.

Wet/Dry filters can cost between $50.00 to $300.00 whether you purchase one or make one from scratch.

Recommended - Wet/Dry Filter

Fluidized Bed Filters

A fluidized bed filter is similar to a sand pool filter in the way it works.

The unit hangs on the back of your aquarium and water is pumped into it. The water is then pushed up and through a mass of granules such as sand, plastic or silica chips.

You will need to purchase a separate pump in order to pump the water into the filter as most do not come with pumps.

Beneficial bacteria grows on the surface of the suspended particles thus providing great biological filtration.

While chemical filtration is not good with this type of setup, mechanical filtration is moderate as the suspended particles trap most of the particulate matter.

These can be expensive filters between $50.00 to $150.00.

Recommended - Fluidized Bed Filter

Lifegard Fluidized Bed Filter
List Price: $82.23
Price: $82.22
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As you can see there are many different types of aquarium filters for you to choose from, which aquarium filter type you get depends on your specific needs.

Technology has really advanced the aquarium filtration systems with many improvements. This aids the hobbyist to keep their aquatic inhabitants easier and to keep species we could only dream of having before.

Before picking your filter, decide on what type and how many of each species you are keeping and what their requirements are for a healthy habitat.

When you take all of that into consideration, you will have less maintenance and more time enjoying long living aquatic life for many years to come.

About Dennis Hanson

Dennis is an experienced aquarist with many years of knowledge and experience in keeping successful tanks. He also has no relations to the pop group Hanson.

3 thoughts on “7 Aquarium Filter Types You Should Know

  1. Reply John McKinley Jan 17,2016 11:55 pm

    How do I decide what type of filter is best for 150 gallon fresh water aquarium?
    I want a system which does adequate job of biological\chemical\mechanical.
    I would like something with UV or oxidizer option to keep algae production down.
    I would like this system to be clean(tubes vs hang on so canister or wet\dry).
    Additionally monthly I need to take all the gravel out to clean uneaten food out of tank. This causes shock in my tank. I’d love an under gravel that sucks the unused food out but any I’ve used just seem to make the issue worse- creating a layer of sludge on the bottom of the tank.

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  3. Reply melody munro Feb 23,2017 10:37 am

    You NEVER take out your gravel and clean it. The “shock” you speak of is due to over cleaning. You are causing your tank too crash and go back into the nitrogen cycle (research this if you dont understand it as it is vital for fish tank health). All you need is a gravel vac and you use this when you do your partial water change. I would get a canister filter if you want a really clean tank.

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