A few days ago, one of my old schoolmates reached out to me and asked for a favor. Since he was quite close to me back those school days, I couldn’t say no. I told him to go further and tell me what he wants from me.

He said, “I wanted to have some Bettas or Koi fishes. Can you tell me which type of filter I should buy?” I thought it would be an easy answer. But as I went on with the discussion I found that the topic circled around canister filter vs. HOB filter.

I was a bit rattled with the discussion since I didn’t anticipate the filter selection to be such difficult. Then, I recalled my old days and found that I also had the same dilemma like my schoolmate is now. So, I decided to research deeply on canister filter and Hang on Back (HOB) filter to help my fellow aquarium owners.

Make no mistake that both filters are great and do a remarkable job on their specific occasions. So, I will just compare their working procedure, maintenance, benefits and finally suggest their best usages in different conditions.

This discussion doesn’t aim to put one filter ahead of another between the canister and HOB filters. So, be aware of it.

Canister Filter Vs. HOB Filter: Which Is Better

Hang on Back (HOB) Filter

Hang on Back (HOB) filters are most commonly known as power filters. These filters sit at the back of your aquarium mostly and so, they got the name. The filtration box is connected with the water inside the tank through an inlet tube.

The inlet tube protrudes in the tank water and carries the water right to the HoB filter container. There it goes past the filtering media and then is sent back to the tank. As the water passes through the filter media it becomes clean and filtered.

The filters mostly come by-default with the aquariums and are the most widely used filter for different aquariums. It works fine for tanks less than 100 gallons. If you have tanks larger than 100 gallons you might want to get a secondary filter for them.


It is because a single HOB filter can’t circulate and regulate such massive water filtration with its limited capacity.

The power or HOB filter will offer you both mechanical and chemical filtration along with minimal biological filtration too. The mechanical filtration is performed using sponge, floss, or foam. The filtration is almost similar to that of a standard sponge filter.

It uses activated carbon for chemical filtration.  When the carbon filter and foams grow older, it also starts acting as a biological filter. It performs the biological filtration with the beneficial bacteria growth in the other two filtering media.

Moreover, some high-end HOB filters come with additional space between their cartridges. You can add extra filtration media there. Also, it supports added biological filtration with the bacteria growth. Thus, you get all three types of filtering facilities with the Hang on Back filters.

Hang on Back filters are easy to set up and so, beginners would find its mounting process easy and comfortable. Similarly, it needs less maintenance. You need to replace the filtering media as instructed in their user-manual.

The downside of the HOB filters is their visibility. Since it sits right at the back or side of the aquarium, it is clearly visible from the front. Also, you can easily see the top of the hang-on back filters. Thus, it limits the aesthetical pleasing feature in your home.

Advantages of HOB Filter:

  • Hang on Back filters are relatively durable and need the least replacement. Thus, it is a worthy investment for beginners. In fact, with proper maintenance, you can expect these filters to last easily for 10 years or more.
  • You can quickly access the HOB filters since it sits right at the tank wall. So, you can reach its filtering media while standing at the aquarium front. It makes the maintenance and filtering media changes easy and comfortable.
  • The installation and application of the HOB filters are easy. These filters work with plug-in and play features. So, beginners would find its installation and application easy.
  • The HOB filters are extremely affordable. In most cases, you will get one HOB filter with the aquarium. So, you at least get a good-quality filter for almost free with the 1st aquarium you purchase. So, if you limit the cash, you must go for the affordable HOB filters.
  • If you have a small to medium fish tank, HOB filters are a must-go option. You can quickly setup it on the tank wall and the inlet tube will reach the tank water. So, you won’t have to be concerned about space in the aquarium.
  • HOB filters such as Fluval and Aqua Clear have the least sound production. So, it is better for fishes who actually needs a peaceful environment.
  • It offers biological, chemical, and mechanical filtering at the same time. It even has extra space for additional chemical filtering.

Disadvantages of HOB Filter:

  • Its water flow efficiency is limited. So, you might need two HOB filters if you have larger or community tanks.
  • A HOB filter is not recommended for biological filtration. It is because the HOB filter doesn’t have sufficient space to help the bacteria grow.
  • The inlet tubes are easily breakable while cleaning. So, you have to be extremely careful while cleaning the HOB filter and its inlet tubes.

Canister Filter

A canister filter comes with a canister-shaped box and so, it gets the name.  It can sit at the back of the fish tank or even underneath it.  The canister is free-standing and easy to mount beside or beneath the aquarium.

It has a cabinet that hides the filter. So, it serves the aquarium aesthetics also. It has two tubes, one inlet, and another outlet tube. These two tubes sit in a submerged condition in the fish tank. Since you have only two hoses inside the aquarium, you can place them anywhere there. Thus, it brings flexibility to the overall canister filter setup.

The best benefit of canister filters is that you can use UV-sterilizer and inline heater with these filters. So, you can add the inline heater with it and still provide enough warmth for the fishes during the cold days. Thus, you save from installing a heater additionally.

Canister filters have multiple chambers inside. You can use several filtering media inside them to offer superior chemical and mechanical filtering. It uses the same sponge, floss, and activated carbon for these two filtration.

Another advantage of a canister filter is its enhanced biological filtering capacity. As it has a larger space, it offers more bacteria growth.

Due to its efficiency in chemical, mechanical, and biological filtration, it is suitable for both planted and saltwater aquariums. It works fine for freshwater aquariums also.

Advantages of Canister Filter:

  • If you have a planted or saltwater aquarium, the canister filters are absolutely a must-go for option. It comes with superior filtration capacity for all three types of filtering systems. So, works best for large tanks also.
  • Canister filters are spacious to accommodate more than enough biological filtering systems. Thus, it boosts bacterial growth and helps maintain the tank water better.
  • You can comfortably install the inline heater inside the canister filter. So, you can still provide enough warmth to the fishes without installing a heater separately.
  • You can also add a UV stabilizer with the canister filter. It filters the UV lights and offers you crystal clear aquarium water.
  • Canister filters are suitable for large and community tanks. It has an efficient water flow controlling capacity. So, it works best for most tanks.

Disadvantages of Canister Filter:

  • The canister filters are extremely highly-priced. You will have to pay 2X to 3X more for the canister filters compared to the HOB filters. So, it is not a valid filter for those with limited cash. Also, beginners would find its pricing expensive.
  • Canister filter setup and maintenance are challenging. You have to properly setup the filters in the separated chambers individually. Thus, beginners might find the installation tough. The maintenance is tough equally.

Canister Filter Vs. HOB Filter: Which One to Buy?

So, it’s time to give my final verdict. Ah, this is always confusing.  But, I have to complete my responsibility anyway.

Thus, here goes my pick –

You should get a HOB filter if you are new to the aquarium world and get a small to medium sized tank. It won’t cost you much and supports easy setup. Also, it works best for small tanks.

When you are experienced and have the confidence to handle complex filters, try the canister filter for your aquarium. Also, if you plan for saltwater or planted aquarium right off the bat, you should choose the canister filter too. However, you should be ready to pay a hefty price for it. So, be aware of the canister filter pricing.

To Conclude

Aquarists often get into a heated debate on canister filter vs. HOB filter. I have found that both canister filter and Hang on Back (HOB) are incredibly good at their jobs. Thus, it is tough to pick one filter over another one.

A canister filter is best for large aquarium owners. Also, it works fine for planted, saltwater, and community tanks. The power filter comes in the package for the aquariums. So, beginners should initiate their aquarium career with power filters.

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