What are the differences between an external filter and one of the filters that hangs on the back of the tank? If you’ve owned an aquarium at some point in your life, chances are you’ve heard that question at some point, and may even have uttered it yourself.
Comparisons between Canister filter and Backpack filter
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They both filter tank water well, so what’s the problem? Believe it or not, there is actually a significant variation between how they both work and their pros and cons. So today we are going to take a closer look at the in-can filter versus the “hanging” filter debate to get to the bottom of it.
The purpose of an aquarium filter
As time goes on, the water in your fish tank will start to get dirty. The inhabitants of your tank, primarily fish and turtles, will excrete waste, accumulate food particles, and increase various toxic compounds that are harmful to your aquarium community.
To remove them from the tank environment, the best option is a strong filter that uses the 3-stage process (combines mechanical, biological, and chemical means to purify the water). Both canister filters and Hang On Back (HOB) filters are capable of this level of water filtration.
backpack filters
HOB filters are considered ideal for beginners due to their ease of use. Also known as power filters, all of its components are self-contained and users simply need to hang them on the back of their tank.
The HOB filter’s internal pump draws water from the aquarium and forces it through the filter’s built-in filter cartridge, which contains the materials needed to purify the water. The inner workings of the HOB filter may vary slightly, but generally involve the same filtration methods.
Filtration
For mechanical filtration, power filters use a standard dental floss or foam. Chemical filtration is done using activated carbon and biological filtration occurs in the previous two stages, as the filter cartridge surfaces promote the growth of beneficial bacteria.
More advanced filters will have additional space for users to include various resins for additional chemical filtration by alternative means and for the incorporation of bio-wheels that allow maximum surface area for beneficial bacteria (resulting in more biological filtration).).
HOB filtering process
There are drawbacks to the HOB filter process. In particular, the mechanical thread clogs easily and must be cleaned frequently to maintain its effectiveness. They are also notoriously difficult to use with freshwater and saltwater tanks.
The reason? Power filters disrupt the surface of the water, drastically altering carbon dioxide levels and also allowing salt to infiltrate the inner workings of the filter. If used with a saltwater aquarium, they will require a higher level of maintenance to keep them functioning.
canister filters
Canister filters, by comparison, have no such problems with saltwater and planted aquariums, and can be used in freshwater as well. A canister is a unit that sits outside the tank and has hoses that can be lowered into the tank to remove and then filter the water.
There are tons of notable brands that offer this type of filter. To name a few, we have Fluval, Marineland and others.
They provide superior levels of both mechanical and chemical filters due to the method by which they pressurize and force the water through its various stages.
biological filtration
Biological filtration can sometimes be limited due to lack of water/air contact (as a result of high pressurization), but this drawback is partially offset by the size of the external filter and the ability to hold large amounts of filter media.
Low biological filtration can also cease to be a problem if an additional biological filter is included. With the combination of a secondary biofilter, canister filters become the primary filters for saltwater and reef aquariums.
They also provide a greater variety of filter media. Often the particular media can be customized, mixed and inserted into canister filters in different amounts to adjust the filtration your tank receives.
ultraviolet light purifiers
Canister filters can also be equipped with ultraviolet light purifiers, which further improve the overall cleanliness of your tank water by treating it with ultraviolet radiation, killing algae spores and other nuisance contaminants.
However, keep in mind that canister filters require a little more dedication than HOB filters, as they are more complicated to set up, have a lot more components, need more media, etc. In exchange, however, you get a filter that is much more powerful, can be used on larger tanks, and can be customized to fit your individual tank setup.
Prices
How much will you pay for these types of filters? In general, your external filter will be the most expensive option. Most HOB filters sit squarely in the $20 to $30 range, while canister filters can often cost upwards of $100, sometimes even topping the $300 mark.
This, of course, is directly related to the increased functionality, versatility, and power you get when using an external filter compared to a power filter (which has greater ease of use, but far fewer worrying features).
The verdict
Although inexpensive and mostly easy to use, HOB filters simply do not provide the same level of performance as canister filters. This is especially important if you have a tank that is large, has a lot of livestock, or may be saltwater (like mine!)
You’ll pay a little more up front, but a good external filter more than makes up for the price by giving you plenty of use, power, the ability to customize filter media, and additional features that further increase your filtration capabilities.
My recomendation? Go all out and get the Fluval FX-6. It’s one of the most powerful canister filters on the market, can handle tanks up to 400 gallons in capacity, and includes many extras (like fluval ‘s auto-start system and smart pump technology) that make it easier to use than many other canister filters. boat..
Do you use a power filter or canister filter in your tank? Perhaps you have multiple configurations and have tried both? Whatever you think, let us know in the comments!
