Best Aquarium Hang-on-Back Filters: Top Picks for 2023

aquarium with hang on back filter

Aquarium enthusiasts know that maintaining a healthy aquatic environment is essential for the wellbeing of their underwater inhabitants. One important aspect of aquarium maintenance is ensuring that the water is free of harmful debris and toxic substances. Aquarium filters play a pivotal role in keeping the water clean and promoting the overall health of the aquarium ecosystem.

Hang-on-Back (HOB) filters are a popular choice among hobbyists as they efficiently cater to the filtration needs of various aquarium setups. These filters efficiently remove impurities from the water by hanging on the side or back of the tank, conserving space and simplifying maintenance. HOB filters typically consist of a compact design, are easy to install, and require minimal effort for upkeep.

When selecting the best HOB filter for your aquarium, it’s essential to consider factors such as the filter’s flow rate, the type of filtration it offers (mechanical, chemical, and biological), and the tank size compatibility. A suitable HOB filter should provide adequate filtration while keeping noise levels low and energy consumption minimal.

Our tests were aimed to focus on the above factors in order to find the best HOB filter. Keep in mind that the below is the results of our tests with our snails and fish set up. Results for your aquarium might be different.

You would also want to check whether HOB filter is the right option for you compared to canister filter or sponge filters.

Our Best Aquarium Hang-on-Back Filter

AquaClear 50 Power Filter for 20-50 Gallon Aquariums

AquaClear 50 Power Filter for 20-50 Gallon Aquariums

Fom all the different HOB filters we tested, we found the AquaClear 50 Power Filter to be the best overall product. Mainly for its efficient performance in maintaining water quality in 20- to 50-gallon aquariums.


  • Superior contact time with filter media
  • Energy efficient pump
  • Optimal mechanical, chemical, and biological filtration


  • Cleaning required every 2 weeks
  • Installation might be challenging for some
  • Some noise may be noticeable

After using the AquaClear 50 Power Filter, we noticed a significant improvement in water clarity within our aquarium. The superior contact time with filter media ensures the water is thoroughly cleaned, while the energy efficient pump reduces operating costs. This three-stage filtration system, including mechanical, chemical, and biological filtration, creates an ideal environment for aquatic life by removing a wide range of impurities.

We appreciate that the AquaClear 50 comes equipped with AquaClear Foam, Activated Carbon Filter, and BioMax, which contribute to the overall water quality. However, to maintain its optimal performance, we recommend cleaning the filter every 2 weeks. While the installation process was quick and easy for us, some users might find it a bit challenging. But with a little patience, it’s definitely worth the effort.

One minor drawback that we came across was a slight noise from the impeller. However, it’s not loud enough to be an issue in most environments. Overall, the AquaClear 50 Power Filter is an excellent product for anyone looking to enhance the health of their aquarium and maintain water quality in a 20- to 50-gallon tank.

Other Note-Worthy HOB Filters We Tested

Penn-Plax Cascade 300 Power Filter

Penn-Plax Cascade 300 Power Filter

The Penn-Plax Cascade 300 Power Filter is another great option for its powerful performance and excellent filtration capabilities in both freshwater and saltwater aquariums.


  • Quiet and efficient operation
  • Adjustable flow and easy mounting
  • Innovative Bio-Sponge cartridge and Bio-Falls system


  • Impeller may be noisy if not seated properly
  • Flow adjustment can be finicky

After using the Penn-Plax Cascade 300 Power Filter in our 100-gallon aquarium, we were impressed by its quiet and efficient functioning. It effectively filtered 300 gallons of water per hour, keeping the tank water crystal clear.

We particularly liked the adjustable flow knob, which allowed us to increase or decrease water flow during feeding times or as needed. The hang-on design made it easy to mount securely, and the lift tube could be adjusted between 8.25″ and 12.25″.

What sets this filter apart is its Bio-Sponge cartridge, which optimizes the colonization of anaerobic bacteria and works independently from the first stage filter media. The Bio-Falls system also contributes to improved water oxygenation and helps remove ammonia and nitrate, making a healthier environment for our aquatic companions.

GRECH CBG-500 5W UV Sterilizer Hang-On Back Filter

GRECH CBG-500 5W UV Sterilizer Hang-On Back Filter

The Grech CBG-500 is an excellent choice for those seeking an efficient hang-on back filter with a UV sterilizer for their 10-30 gallon aquariums.


  • Adjustable filter flow rate with surface skimmer
  • 5W UV Sterilizer to keep water clear
  • Biological and mechanical filtration with included media


  • May be too strong for some smaller tanks
  • Lack of UV light indicator
  • Noisy for some users

We recently used the GRECH CBG-500 in our aquarium setup and were impressed with its unique design and ease of installation. The adjustable flow rate and surface skimmer proved to be very helpful in eliminating undesired surface films and maintaining a healthy aquatic environment.

The 5W UV sterilizer is a standout feature, as it eliminates algae and bacteria, keeping the aquarium water crystal clear. This not only enhances the overall appearance of the tank but also contributes to the well-being of the aquatic inhabitants. However, we did notice that there is no indicator to show if the UV light is on or off, which can be slightly inconvenient.

While the CBG-500 filter is suitable for both freshwater and saltwater tanks and comes with active carbon and bio media for biological and mechanical filtration, it may be too powerful for smaller aquariums. Additionally, some users experienced noise issues – though this was not a significant problem for us during our time with the product.

Generic 8W UV Sterilizer Hang-On Back Filter QF-09

Ultraviolet sterilizer suspended multiple filter

The Generic 8W UV Sterilizer Hang-On Back Filter QF-09 is a top-notch choice for aquarium enthusiasts, providing multi-stage filtration and UV sterilization for a cleaner, healthier aquatic environment.


  • 3W UV sterilizer eliminates unwanted algae and bacteria
  • Multi-functional design saves time and effort
  • High-quality materials ensure durability and safety


  • May require 2-3 days for noticeable improvement in water quality
  • Not suitable for larger aquariums beyond 20 gallons
  • Relatively new with limited customer feedback

Our experience with the Generic 8W UV Sterilizer Hang-On Back Filter QF-09 has been impressive. This economical filter not only saves us money but also helps maintain a clean and safe aquatic environment for our fish. The combination of mechanical, chemical, and biological filtration processes, along with the UV sterilization, ensures that our aquarium remains healthy and vibrant.

The UV sterilizer feature is truly an aquarium must-have, as it assists in getting rid of algae and bacteria. This results in a crystal-clear tank that we are proud to display. The high-quality materials used in its construction, such as food-grade ABS plastic, stainless steel, and quartz glass, make it durable and safe for our fish. The ease of operation and installation makes using this hang-on filter a breeze, adding to the overall pleasant experience.

On the downside, the time taken to see significant water quality improvement may be longer than expected (2-3 days). Moreover, with a capacity limited to aquariums up to 20 gallons, it may not be suitable for larger setups. Lastly, the availability of only three customer ratings means limited feedback, but our personal experience has been highly positive, and we highly recommend this Hang-On Back filter for aquarium enthusiasts looking for a great value purchase.

Penn-Plax Cascade 150 Power Filter

Penn-Plax Cascade 150 Power Filter, Hang-On Filter with Quad Filtration, Great for Freshwater and Saltwater Setups

We recommend the Penn-Plax Cascade 150 Power Filter for its efficient performance and versatility in both freshwater and saltwater aquariums.


  • Quiet and efficient filtration
  • Adjustable flow rate
  • High-quality filtration media


  • May require frequent cleaning
  • Flow adjustment range is limited
  • Motor durability concerns

While using the Penn-Plax Cascade 150 Power Filter, we noticed right away that this hang-on filter operates quietly while effectively filtering the water in our aquarium. With a flow rate of 150 GPH, it can handle tanks up to 35 gallons in size. Its adjustable flow knob is quite handy during feeding times and can be tailored to suit your aquarium’s needs.

The filter features disposable, double-sided media cartridges containing activated carbon and poly fiber floss which ensure the removal of harmful chemicals and toxins as well as floating particulate matter. The Cascade 150 also has a Bio-Sponge cartridge that promotes colonization of anaerobic bacteria, working independently from the first stage filter media. This, combined with the Bio-Falls system, improves water oxygenation and helps with ammonia and nitrate removal.

However, we did experience a few drawbacks to this filter. Despite its outstanding filtration capabilities, the need for frequent cleaning might be an issue for some users, and the range of flow adjustment could be better. Some users also reported motor durability concerns, but these instances appear to be rare. Overall, the Penn-Plax Cascade 150 Power Filter is a reliable hang-on filter, offering efficient and versatile filtration in both freshwater and saltwater aquarium setups.

Buying Guide

When it comes to choosing the best Hang-on-Back (HOB) filter for your aquarium, there are several factors you need to consider. In this buying guide, we focused on the most important features and aspects below in a high-quality HOB filter, so you can make the best decision for your aquarium and your snails & fish.

Flow Rate

The flow rate of a HOB filter is crucial, as it determines how effectively and quickly the water is filtered. It’s important to choose a filter with an appropriate flow rate for the size of your aquarium. As a general rule, the filter should be able to process the entire volume of your aquarium at least 3 to 5 times per hour. For example, if you have a 30-gallon aquarium, you should look for a filter with a flow rate of at least 90 to 150 gallons per hour (GPH).

Filtration Stages

A high-quality HOB filter should offer multiple stages of filtration to ensure optimal water quality. This typically includes mechanical, chemical, and biological filtration. Mechanical filtration removes debris and solid particles, while chemical filtration helps neutralize toxins and impurities. Biological filtration promotes the growth of beneficial bacteria that break down harmful substances. Make sure the filter you choose supports all three stages for the best results.

Media Compatibility

The filter media used in a HOB filter plays a major role in its effectiveness. It’s essential to choose a filter that supports various types of filter media, preferably one that is compatible with both standard and custom media options. This will enable you to fine-tune your filtration system to meet the specific needs of your aquarium and its inhabitants.

Easy Maintenance

Regular maintenance is crucial to ensure the longevity and efficiency of your HOB filter. Consider a filter that is easy to clean and maintain, with readily available replacement parts and filter media. This will save you time and effort in the long run, helping you keep your aquarium in optimal condition.

Noise Level

Lastly, consider the noise level of the HOB filter you choose. Most quality filters have quiet operation, but some may produce more noise than others. If you have a preference for a quieter filter, pay attention to the noise levels advertised by the manufacturer or other customers’ experiences in reviews.

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