Hang on back filters (HOB or power filter) and canister filters are two of the more popular filters used by aquarium hobbyists for both freshwater and saltwater. They both have their pros and cons which always relate to the size of tanks being used as well as whether you have a freshwater or marine setup.
HOB vs canister filters, which one is best? Both types of filters do an excellent job in filtering aquarium water. Both filters also, have the ability, to harbor healthy bacteria which is essential to the success of an aquarium and its livestock. The best HOB filter or canister filter will depend on your tank size and requirements.
I use both types of filters with great success. It’s true that the size of your tank sometimes dictates which type of filtration you should use. However, I have used a larger Aquaclear filter on a 55-gallon tank with no problems at all. Once you understand the benefits of using either filter, the choice on which one to use is that much easier. In this article, I will provide you with my take on the pros and cons for each filter and where I feel they are most useful. Let’s get started!
What is the Difference between a Canister Filter & Power Filter?
A power filter, which is another name for HOB filters, are recognized by the fact that they hang onto the sides or back of an aquarium. It has an inlet tube that protrudes into the tank’s water and sucks up water into the filter. The water is drawn inside the filter’s body via the inlet tube and then flows through your filter media before being pushed back out into the tank.
The HOB’s inlet tube and possibly the body of the filter are always visible. The top of a HOB filter is visible at all times. HOB’s are typically not recommended for tanks over 100 gallons. Reason being is the tank’s water will not circulate properly with this type of filter and the amount of water needed to be filtered in a much larger tank.
I have a 10-gallon tank with an Aquaclear HOB and it works perfect for this size tank. I can’t imagine trying to hook up a canister filter to this size of a tank!
Canister filters are freestanding units shaped somewhat like a canister. These are external filters, typically stored hidden away from the aquarium possibly underneath in a cabinet or off to the side, unlike a HOB style of filter.
A canister filter has two tubes, one for inlet and one for outlet. The water is drawn in one tube through the filter media and out the outlet tube back into the tank. There are two major differences here between the canister filter and HOB.
- With a canister filter, the only thing entering the water (aside from the water) are 2 tubes (hoses) so they can be extended and placed (moved around) to either end or sides of your tank. This allows for maximum water flow to make sure most floating debris gets picked up among other things. Your fish also enjoy more water movement than you probably know. Unless of course you are keeping species such as bettas or sea horses.
- The other HUGE difference between a canister filter and a HOB filter is with a canister you can add an inline heater as well as a UV sterilizer. If you don’t want a heater in your tank, then using a canister filter with an inline heater is the way to go. Also, you get the added benefit of using an inline UV sterilizer instead of a separate unit that sits in the aquarium taking up space.
Canister filters can be used for smaller aquariums and they are being utilized for them more so now than in previous years. Canister style filters are still the go-to type of filtration for a larger tank, especially over 100 gallons. Having said that, I now realize I have only a 75-gallon set-up with a canister filter! I like it because it fits underneath in a cabinet and is easy to access and clean.
Canister Filter Pros and Cons (Why Use One?)
The following pros and cons are based on my own experiences.
- Canister filters are easy to access for maintenance or if there is ever an issue. I keep mine in its own compartment under my tank. Whether you need to clean or change filter media, it’s super easy with this type of filter.
- Most canister filters have more than enough space in them to successfully grow enough beneficial bacteria for the tank. This allows you to keep the aquarium itself squeaky clean without worrying about killing off too much bacteria.
- Most canister filters are very quiet, especially when they are tucked away in a cabinet. You could even insulate the cabinet on the inside to make it even quieter.
- Inline heating is easy to install if you don’t want a heater in your tank.
- An Inline UV sterilizer can be installed if you want crystal clear water. It is amazing what these pieces of equipment can do.
- Canister filters are now reasonably priced. Not too long ago you had to save up for a while to be able to afford one of these units. Nowadays, even canister filters for very large tanks are moderately priced.
- Canister filters stand out like a sore thumb, if you don’t have the right set up for one. If you have a cabinet under your tank or a way to hide it off to the side, then it won’t obviously stand out. Think about that though before you go and purchase one.
- Unless you have a control for rate of flow, you might buy one that is too powerful for your tank. Make sure to check this as well before purchasing. I think most new ones have this feature so it might only apply if you are buying a used one.
I would recommend it to anyone that can afford one to go ahead and get one if your tank is 50 gallons or larger. And, if it is over 100 gallons, then it only makes sense. You could get away with a HOB for a 50-gallon but why bother if you can afford a canister?
HOB Filter Pros and Cons (Why Use One?)
- I have had HOB filters that have lasted over 10 years easily. In fact, I just replaced one recently that must have been over 15 years old. These filters are extremely durable in my experience.
- A HOB filter can be very easy to access. Provided it is in arm’s length while standing at your tank you should be able to work on it doing maintenance quite easily. You just have too unplug it then pull out the aquarium media.
- HOB filters are very affordable. If you were considering a canister filter but don’t quite have enough cash, don’t think twice about grabbing a HOB instead. These filters are worth every penny and more.
- HOB filters are my go-to for small tanks. I like how you can hide it by hanging it on the back of the tank. Then, all that sticks in the aquarium is the inlet tube.
- For sound, I have never had a problem with my Aquaclear and FLuval HOB filters. If there ever is any sound, it’s usually a loose lid that just needs to be pushed down.
- The water flow with these types of filters would not be as efficient in a larger tank. I have heard and read where some hobbyists will have 2 HOB filters on a larger tank. This set-up works, however, it’s also an indication you might just need to level up and purchase a canister style filter.
- When it comes to housing beneficial bacteria in a HOB filter, there might not be enough space for enough of the bacteria to grow for the size of tank you have. If your main goal when it comes to beneficial bacteria to have it growing healthily in your filter, then maybe a HOB is not the right one to use. Or, you could maybe consider keeping beneficial bacteria in the tank’s substrate instead.
- If you are not careful, the inlet tubes can crack or break easily when taking out to clean. I say this from my own experience and maybe I am just too rough on them, even though I try my best not to damage anything.
Are Canister Filters Better Than HOB’s?
I hear this question a lot from new aquarium enthusiasts. They are and they aren’t. For a smaller tank, HOB filters are the way to go in my mind. It’s when you’re starting to get into the larger tanks, such as anything 50 gallons and larger, that it makes sense to use a canister filter.
In conclusion, it should be clear which filter is best for you now, correct?
For smaller tanks under 50 gallons, think of using hang on back filters first and anything 50 gallons and over think about using canister filters first. This doesn’t mean you can’t use a large HOB on a 50-gallon tank because many people do. It’s just not an optimal filter for the movement of your water. You could also use a power head to help move the water. A lot of hobbyists, however, don’t like adding equipment to their tanks, if they don’t have to.
Good luck and happy fish keeping!
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