Hang-on-back (HOB) filters are one of the most popular aquarium filters. They are easy to install and can be mounted on the side of an aquarium using a clip or hanger. It is also convenient to maintain them and replace their filtration media due to their open design. Some of them can also create a waterfall-like effect that looks pleasing. Here are the best hang-on-back (HOB) filters that will suit aquariums with varying capacities.
1. Marina Power Filter

Marina Power Filter is a great option for small aquarium owners who are looking for the best hang-on-back (HOB) filters. It is equipped with Bio-Carb and Bio-Clear filtration cartridges. They get rid of unwanted particles and impurities and maintain ideal living conditions for aquatic life. You can adjust the flow rate of the water depending on your fish species and tank size. Its pump has a self-priming capability and is easy to maintain. Marina Power Filters come in three variants that will suit fish tanks with capacities of up to 10 gallons, 15 gallons, and 20 gallons respectively.
2. Tetra Whisper Power Filter for Aquariums

Tetra Whisper Power Filter is one of the best hang-on-back (HOB) filters. The filter cleans aquarium water in three stages. Its first stage traps debris and fish waste using a dual-sided mesh. The second stage gets rid of odors and discoloration using activated carbon. Bio-Foam in the final stage promotes aerobic bacteria growth for breaking down ammonia and nitrites. It is equipped with large Bio-bag cartridges that have excellent filtration efficiency and are easy to replace. Tetra Whisper Power Filters can be purchased in four different sizes for fish tanks up to 60 gallons.
3. GRECH CBG-800 UV Sterilizer Hang-On Back Filter

GRECH CBG-800 is another UV alternative among the best hang-on-back (HOB) filters. It comes with a 5W UV bulb for sterilizing the water and getting rid of floating microorganisms like algae. Your aquarium water won’t lose its color over time. The UV light can be turned on or off independently. The filter comes with activated carbon and biofiltration media for mechanical and biological filtration. It has a maximum flow rate of 211GPH and can be used for 20 to 50-gallon aquariums. You can adjust the flow rate as required. It also has a built-in surface skimmer.
4. Penn Plax Cascade Hang-on Aquarium Filter With Quad Filtration System

Penn Plax Cascade is a popular choice of the buyers who are searching for the best hang-on-back (HOB) filters. Its four-stage filtration removes biological, chemical, and mechanical impurities from your aquarium’s water. It uses a poly-fiber floss cartridge for trapping waste particles and a sponge for promoting the growth of beneficial bacteria. It also has an activated carbon cartridge for removing chemicals and contaminants that may cause odors and discoloration. You can adjust the water flow rate using a knob. The filter is suitable for freshwater and saltwater aquariums and is available in multiple sizes that will suit up to 100-gallon tanks.
5. Aqua Clear Power Fish Tank Filter

Aqua Clear Power Filters are a highly sought-after item on the list of the best hang-on-back (HOB) filters. The filter uses AquaClear foam for removing debris and unwanted particles, activated carbon for absorbing odor-causing impurities, and BioMax ceramic rings for promoting the growth of bacteria that remove ammonia and nitrites. Its long water-to-media contact time ensures superior filtration capability. It is easy to install and maintain as well. Aqua Clear Power Filters come in multiple sizes that will be suitable for fish tanks with capacities ranging from 5 gallons to 110 gallons.
6. Aqueon QuietFlow LED PRO Aquarium Power Filters

Aqueon QuietFlow is a well-selling product among the best hang-on-back (HOB) filters. It filters water in five stages to keep your aquarium clean and fishes healthy. The mechanical, chemical, and biological media ensure optimum filtration. It also has specialty pads besides the dense floss, activated carbon, and bio-holster for removing additional toxins while improving the oxygen levels of the water. It uses a self-priming pump that makes it easy to restart the filter after maintenance or power interruptions. An LED on the filter monitors water levels and starts flashing when the filter cartridges require replacement. Aqueon QuietFlow LED PRO power filters come in filtration capacities ranging from 100GPH to 400GPH.
7. Fluval C Power Filter

Aquariums owners searching for the best hang-on-back (HOB) filters can also consider the Fluval C Power filter. Its five-stage filtration process ensures optimal living conditions for the aquatic life in your fish tank. The first two stages use porous foam and dense polyester for mechanical filtration. Then the activated carbon insert gets rid of chemical impurities. Next, the water flows through a Bio-Screen for removing any remaining debris. The final stage consists of C-Nodes that promote the growth of beneficial bacteria that remove ammonia and nitrites. It can be installed on the back of a tank with a clip and is easy to maintain. There are three variants of the Fluval C Power Filter available that will suit up to 30-gallon, 50-gallon, and 70-gallon aquariums respectively.
8. MarineLand Penguin 200 BIO-Wheel Power Filter

When it comes to the best hang-on-back (HOB) filters, MarineLand Penguin 200 BIO-Wheel Power Filter is a great product. It provides three-stage filtration for removing mechanical, chemical, and biological impurities in the water. Your fish tank will be free from waste, odors, and discoloration. Its Bio-Wheel is specifically designed to tackle ammonia and nitrites in the water while promoting the growth of beneficial bacteria. This model has a flow rate of 200GPH and will be suitable for 30 to 50-gallon aquariums. MarineLand Penguin BIO-Wheel Power Filters are also available in smaller and large capacities.
9. AquaTop PF40-UV Power Filter (HOB) with UV Sterilization

AquaTop PF40-UV is a versatile product among the best hang-on-back (hob) filters. It has a 7-Watt UV bulb in addition to mechanical and chemical filtration media for keeping your fish tank clean and healthy. The bulb gets rid of free-floating algae and parasites. There is a self-adjusting skimmer in the unit as well for cleaning the surface of the water. The filter uses a 7-Watt pump that has a flow rate of 128GPH. It will be able to filter water efficiently in 15 to 40-gallon aquariums. A knob allows you to adjust the flow rate as required. You can use AquaTop PF40-UV Power Filter in freshwater and marine setups. Smaller variants of this HOB filter are also available.
10. Aqua-Tech Power Aquarium Filter w/ 3-Step Filtration

Aqua-Tech Power Filter is a popular choice of the buyers who are looking for the best hang-on-back (hob) filters. It uses a 3-stage filtration process for keeping aquariums clean. The filter comes with coarse floss for mechanical filtration, activated carbon to get rid of odors and discoloration, and Bio-Tech Biological Grid for eliminating ammonia and nitrites. It is easy to install and maintain thanks to its HOB design. Aqua-Tech Power Filters are available in four different sizes that will be suitable for 5 to 15-gallon, 10 to 20-gallon, 20 to 40-gallon, and 30 to 60-gallon aquariums respectively.