Aquarium Filters – Hang On Back vs Canister vs Sponge: A Concise Comparison Guide

Aquarium with filters

When it comes to setting up a thriving aquarium, choosing the right filtration system is essential. There are several types of aquarium filters available, each with its advantages and disadvantages. Among the most popular filter types are hang on back (HOB) filters, canister filters, and sponge filters. This article will provide an introduction to these three filter types and help aquarium enthusiasts determine which one is best suited for their specific needs.

Hang on back filters, as the name suggests, simply hang on the back of the aquarium and draw water through an intake tube. These filters are easy to install and maintain, making them a popular choice for beginners. Canister filters, on the other hand, are external units that sit outside the tank and utilize hoses to remove and filter water. Canister filters are well-suited for planted and saltwater aquariums, as well as larger tanks with a higher number of aquatic inhabitants.

Sponge filters are often recommended for aquariums with small or slow swimming fish and smaller tanks, as they provide gentle filtration that won’t create too much water movement. These filters operate by using an air pump to drive water through a sponge, which traps debris and provides biological filtration. With a basic understanding of these filter types, aquarium enthusiasts can make an informed decision on the best filtration system for their tank.

aquarium with hang on back filter

Hang on Back Filters

Hang on Back (HOB) filters are a popular choice for aquarium enthusiasts, as they are easy to use and maintain. They are called HOB filters because they are designed to hang on the back of the fish tank, making them a convenient option for most aquarium setups.


One of the main advantages of HOB filters is their ease of use. They are simple to install by just hanging them on the back of the tank, and they require minimal space. This makes them suitable for both small and large tanks. HOB filters are also versatile, as they can perform mechanical, biological, and chemical filtration, depending on the product you buy.

Another advantage of HOB filters is their affordability. They are, in general, less expensive than canister or sponge filters. HOB filters are also easier to clean and maintain, as the filter media can be simply removed and replaced or cleaned as needed, without needing to disassemble the entire filter unit. This makes them an attractive choice for beginners and experienced aquarists alike.


Despite their advantages, HOB filters do have some drawbacks. One of the most notable disadvantages is the limitation in their capacity for filter media, which can lead to inadequate filtration in larger tanks or tanks with a high bioload. For this reason, they may not always be the best choice for heavily stocked tanks or tanks containing larger snail and fish species.

Additionally, HOB filters can be noisier compared to other filter types due to vibrations from the motor or the water flowing through the filter. This can be a concern for some aquarists who prefer a quieter aquarium environment, especially if the aquarium is situated in a living area or bedroom.

aquarium with canister filter

Canister Filters

Canister filters are a popular choice for aquarium enthusiasts, known for their efficiency and versatility. These filters are typically situated outside of the aquarium and connected to the tank via hoses.


One of the significant advantages of canister filters is their compatibility with a variety of aquarium types, including freshwater, saltwater, and planted tanks. Additionally, they have a larger capacity for filter media compared to hang-on-back (HOB) filters, which enables better water filtration and provides the option to customize the filter media.

Canister filters also offer an impressive filtration rate due to their powerful pumps, which contributes to maintaining better water quality and clarity in the aquarium.


Though canister filters have many benefits, they also have some drawbacks. One of the main disadvantages is that these filters can be more difficult to clean compared to other filter options. Proper maintenance is crucial for optimal performance, and neglecting to clean a canister filter can have negative effects on water quality over time.

Additionally, canister filters may have a higher initial cost compared to other styles, such as sponge or hang-on-back filters, making them a more significant investment for aquarium owners.

Sponge Filters

Sponge filters are simple and cost-effective devices used in aquariums to maintain water quality. They rely on an air pump to pull dirty aquarium water through a fine sponge tip which filters out waste particles and traps them on the sponge’s surface. The clean water then circulates back into the tank through the filter’s outflow tube.


There are several advantages to using sponge filters in aquariums:

Simple and affordable: Sponge filters are generally inexpensive, easy to maintain, and require minimal setup.

Gentle water flow: They produce a gentle flow of water, making them suitable for aquariums with slow-swimming or small fish.

Biological filtration: The sponge provides ample surface area for beneficial bacteria to grow, promoting biological filtration and helping maintain a healthy aquatic environment.

Low maintenance: Cleaning a sponge filter typically involves squeezing it out in a container of tank water, making maintenance quick and easy.

aquarium without filter


Despite their benefits, sponge filters also have certain drawbacks to consider:

Limited filtration capabilities: Sponge filters mainly provide mechanical and biological filtration, but they lack chemical filtration, which can be necessary for removing specific contaminants or keeping the water crystal clear.

Aesthetics: Some aquarists find sponge filters to be visually unappealing or obtrusive, as they are placed inside the tank and can take up valuable space.

Not ideal for large or heavily stocked tanks: Sponge filters may not be sufficient for larger aquariums or tanks with a high fish population, as their filtering capabilities might not keep up with the bioload.

Factors to Consider

When choosing an aquarium filter, there are several factors to consider before making a decision. These factors include fish tank size, type of aquarium, budget, and maintenance. Each type of filter has its own advantages and disadvantages, so it’s crucial to weigh these factors to determine the best fit for your aquarium.

Fish Tank Size

One of the foremost factors to consider is the size of your snail tank. For smaller aquariums, a Hang On Back (HOB) filter or sponge filter may suffice since they do a fine job with smaller volumes of water. However, for tanks larger than 55 gallons, canister filters are recommended since they are better suited for larger water volumes.

Type of Aquarium

The type of aquarium also plays an essential role in filter selection. Sponge filters are ideal for aquariums with small, slow-swimming fish and low to moderate bioloads. Canister filters, on the other hand, are better suited for large tanks with numerous aquatic animals or aquariums with fish that require stable environments with efficient filtration.


Budget is another important aspect to consider. Sponge filters tend to be the most affordable option, making them suitable for hobbyists on a tight budget. Canister filters, while offering superior filtration, generally come at a higher cost. HOB filters fall in between these two options when it comes to pricing. Assessing your budget and the filtration needs of your aquarium will help you decide the most cost-effective choice for your situation.

saltwater aquarium


Lastly, consider the maintenance involved in each type of filter. Canister filters may require more maintenance, as they necessitate more time and effort to clean. HOB filters, on the other hand, are relatively easy to maintain, with straightforward access to filter media for cleaning and replacement. Sponge filters are also low-maintenance, with cleaning usually involving simply squeezing out the sponge in used tank water.

By considering the factors of fish tank size, type of aquarium, budget, and maintenance, you can make an informed decision on the best type of filter for your specific needs and preferences.


In the end, choosing the right aquarium filter depends on the specific needs of your tank and its inhabitants. Each of the three main types of filters—hang-on-back, canister, and sponge filters—has its own set of advantages and drawbacks.

Hang-on-back filters are easy to maintain, offer efficient filtration by employing a multi-stage process, and are mostly invisible when placed at the back of the aquarium. Canister filters, on the other hand, provide powerful filtering capability, can easily accommodate larger tanks, and are quietly located outside the tank. Finally, sponge filters are an affordable option, offer excellent biological filtration, and are ideal for tanks with delicate or slow-moving species.

To make an informed decision, consider the following factors:

  • Size and bioload of your aquarium
  • Types of snails, fish and aquatic life you plan to house
  • Maintenance requirements and ease of cleaning
  • Budget and available space

By evaluating your aquarium’s specific needs and thoroughly researching the pros and cons of each filter type, you can confidently select a filtration system that will keep your aquatic environment healthy and thriving.

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