This page contains affiliate links.  All that means for you is that if you click on one of my links and make a purchase, I receive a small commission.  This helps me keep this content 100% free!  But rest assured, I only recommend products I know and trust! Happy Reefing!

Top Five Beginner Hang On The Back Filters & Refugiums

Updated 2023

The Berlin Method has long been a traditional approach to maintaining a saltwater aquarium, relying on a sump, protein skimmer, and ample live rock for filtration. However, having a sump is not mandatory for achieving decent filtration. You can actually save money by opting for an affordable glass aquarium and employing a Hang-On-Back (HOB) filter.

In this post, I’ll recommend three different types of HOB filters:

1. Power Filter: This is the standard HOB filter that utilizes a small utility pump to draw water from the tank into the filter. Various filter media are placed inside, allowing water to pass through before being returned to the tank.

2. Power Filter with Protein Skimmer: A beefed-up version of the standard HOB filter. By adding a protein skimmer, you can more effectively clean your water column.

3. Refugium: For high-nutrient systems with abundant livestock, a refugium with macroalgae can be set up. It provides a habitat for copepods and amphipods while aiding in phosphate and nitrate export through algae growth.

Though I’ve personally used the Penn Plax Cascade 300 and still rely on it for my 40-gallon breeder tank, the order of preference in this post is somewhat flexible. Each item listed offers unique features, and the best choice will ultimately depend on your specific needs and requirements!

5. CPR Aquatic AquaFuge 2 Large HOB Refugium

The CPR Aquatics Refugium is an excellent choice with impressive features. It includes a powerhead. The baffled housing design allows for the addition of live sand or Miracle Mud substrate, enhancing its effectiveness.

While the refugium itself doesn’t come with a light, the Innovative Marine Aqua Gadget Chaetomax Refugium LED is a great companion. It conveniently mounts using velcro, adhering seamlessly to the back of the CPR Refugium.

Both CPR Aquatics and Innovative Marine are renowned for producing high-quality products, making the combination trustworthy based on positive reviews.

Keep in mind that this HOB refugium has a generous size, measuring 25″L x 4″W x 11.8″H (43cm x 8cm x 32cm), so ensure you have ample space before making your purchase.

By utilizing this HOB refugium, you can effectively reduce nitrates and phosphates, while creating a safe breeding habitat for various species of pods. This enables you to house certain fish species like Mandarin Dragonets with greater success.

4. CPR AquaFuge2 Small HOB Refugium

The CPR AquaFuge is indeed similar to #5, but it offers greater flexibility with three different size options, allowing for better customization to suit your needs.

Like its counterpart, it includes a small utility pump, but remember that a separate light is required. For this HOB refugium, the waterproof Tunze Ecochic LED refugium light is a suitable choice and will complement its performance effectively.

3. Marine HOB Breeding Box

This Marine HOB Breeding Box serves as a safe haven for fish, offering a refuge to minimize aggression when introducing new fish into an established tank. While it may not be a conventional refugium designed for growing macroalgae, it still fulfills a valuable role in the aquarium.

If you encounter situations where certain fish face harassment from tank mates, this breeding box provides a natural sanctuary for them to escape to. The gentle flow inside the box is achieved through an air pump, making it necessary to acquire both an air pump and airline tubing, which can be easily found through a standard airline tubing link provided.

2. AquaMaxx HOB-1.5 Protein Skimmer

The AquaMaxx HOB-1.5 is an advanced and more powerful version of their popular HOB-1 protein skimmer. The upgrades include an enlarged bubble diffusor and reaction chamber, allowing the Shark 1.0 pump to maximize foam production and protein extraction. Custom conical bubble diffusors minimize turbulence and direct water flow towards the collection cup, effectively removing more waste from your aquarium.

Setting up and maintaining the AquaMaxx HOB-1.5 is hassle-free. Adjusting the foam level to wet or dry is a breeze by moving the collection cup up or down. Cleaning is made easy with the removable collection cup, and the skimmer includes a drain fitting for hobbyists who prefer a separate reservoir for skimmate.

AquaMaxx protein skimmers are thoughtfully designed to save space, reduce noise, and improve efficiency. The pump is integrated inside the skimmer, and each unit is crafted from polished cell-cast acrylic for durability and precision.

Performance is enhanced with high-quality Sicce pumps, modified and fitted with AquaMaxx needle wheel impellers. The upgraded AquaMaxx ‘Shark’ pump draws in more air and creates optimal bubble sizes for efficient protein skimming.

1. Penn Plax Cascade HOB Power Filter

While the Penn Plax Cascade HOB power filter might not be the top-rated option on the market, it offers incredible value for its $45 price point. I personally use the Cascade 300, designed for 55-100-gallon aquariums, on my 40-gallon breeder tank, and it performs admirably, providing a slight overpowered advantage that I find beneficial.

Available in various sizes, the Cascade series provides a straightforward setup with a basic utility pump, a removable plastic baffle, and a simple black sponge. I usually use filter floss in the rear chamber, occasionally adding a mesh bag filled with activated carbon.

For those willing to invest an extra $250, the AquaMaxx HF-M HOB Filter with Protein Skimmer, listed as #2 in this post, is a fantastic choice. However, if you’re setting up a simple tank without the need for anything extravagant, this affordable Penn Plax HOB will serve you well.