The 5 Best Hang On Back (HOB) Filters for Aquariums

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When it comes to your aquarium, there’s nothing more important than creating the perfect, healthy environment for your fish. They need the right lighting to help them thrive and grow. They need the right temperature, the right substrate, and the right plants and decorations to hide and dart and stay healthy.

And even more important, they need clean, clear water that’s been purified, with the right pH balance that has that wonderful, beneficial bacteria hanging around. And that means finding the right filter.

Below, you’ll find our expert reviews of the best hang on back filters.

Best hOB Filter Quick-Find Table

Image Product
  • Great for tanks up to 110 gallons, depending on the model
  • Multi-stage filtration for the purest water
  • Probably your best bet for a hang on back filter for saltwater
  • Great for tanks up to 110 gallons, depending on the model
  • Multi-stage filtration for the purest water
  • Probably your best bet for a hang on back filter for saltwater
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  • Self-priming aquarium filter
  • Perfect for small tanks – 3 sizes [10, 15, and 20 gallons]
  • Has an adjustable flow rate
  • Self-priming aquarium filter
  • Perfect for small tanks – 3 sizes [10, 15, and 20 gallons]
  • Has an adjustable flow rate
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  • Super quiet and easy on sensitive ears
  • Uses StayClean technology for the cleanest tank around
  • Has adjustable flow rate control
  • Super quiet and easy on sensitive ears
  • Uses StayClean technology for the cleanest tank around
  • Has adjustable flow rate control
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  • Simple and straight forward installation and maintenance
  • Great for freshwater tanks up to 50-gallons
  • Practical and adjustable to meet your aquarium needs
  • Simple and straight forward installation and maintenance
  • Great for freshwater tanks up to 50-gallons
  • Practical and adjustable to meet your aquarium needs
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  • Powerful
  • Super cleaning power with the right media
  • Easy adjustable flow rate for feedings and cleanings
  • Powerful
  • Super cleaning power with the right media
  • Easy adjustable flow rate for feedings and cleanings
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What are HOB Filters?

Hang on back – or HOB – filters are the type of filter that hangs on the back of your aquarium, just as the name implies. Part of the filter is submerged in the water, which is how the filter gains access to the water for purification purposes.

best hang on back hob filter

They’re technically classed as simple external filters, though they’re not as bulky as canister filters. They’re good for use in a variety of tanks, though if you have a large aquarium, you’ll need a few HOBs to keep things flowing smoothly and staying clean.

When to Choose HOBs Over Other Filters

Not all aquariums are suited to the use of HOB filters. Small ones thrive with these devices, but larger aquariums and most saltwater tanks do not receive as much power for filtration as necessary when using an HOB.

Small Tanks

Since HOBs are relatively small, they’re well-suited for use in nano reef tanks and small aquariums under 15 or so gallons of water. 

Tight Budgets

HOB filters are great for those on tight budgets. They cost less than larger filters – think canister filters that can run into the hundreds of dollars range – and the parts are usually easily replaceable.

Easy Cleaning Needs

If you travel a lot or generally just don’t have much time to clean your aquarium filter, HOBs are a great choice for you, as well. They’re easy and quick to clean.

And as long as you get a high enough quality filter, you won’t need to clean it terribly often, assuming it’s in a tank of the appropriate size.

Beginner Aquarists

Finally, if you’re a new hobbyist and don’t have a lot of experience working with aquariums and filters yet, you may wish to choose a HOB filter for the sheer ease of use.

The filters require little attention, low maintenance, and are incredibly easy to install and use.

Drawbacks of HOB Filters

The primary drawbacks for HOB filters are as follows:

  1. They’re fairly low power. This means they’re not good for large aquariums.
  2. They’re not very versatile. This means you have limitations on how you can effectively use them in your aquarium environment
Rhodactis uder blue lights best hob filter

HOB vs Canister Filters

If you’re on the fence on whether or not a HOB is the right option for your aquarium, take a look at the comparison below between HOB and canister filters, the two primary options you’ll find around.

The Size

The size of the filter is the most noticeable difference between the two styles of filters.

HOBs tend to be small and sleek, while canister filters are rather large external devices that take up a lot more space.

If you’re trying to save on space, you’ll want to go with the HOB. If you’re looking to filter a large aquarium, you can buy a few HOBs or go with the larger canister filter.

The Effectiveness

Canister filters can store more media, which means you have a lot more versatility in filtration, and more effectiveness in filtration. HOBs can’t sustain larger aquariums, generally.

But if you have a small aquarium, you don’t need the larger canister, unless you have very delicate fish, live rocks, coral, or plants.

The Price

The other huge difference between the two is the price tag. HOB filters are much more budget friendly than canister filters.

If you’re on a tight budget, you may consider using HOBs more easily than canisters for this reason alone.

Overall

If you are keeping a small aquarium, a HOB filter is probably the better choice. They’re less expensive, easier to use, and do a sufficient job.

If you’re keeping a larger aquarium, though, you’re probably better off with the more powerful canister filter that can handle a larger amount of water.

How to Choose Your HOB Filter

There are a few things you’ll want to keep in mind as you shop for your HOB filter.

  • Required Flow
  • Size of Tank
  • Media Type

Required Flow

The first thing to think about with the filter in any aquarium is the required flow rate. This required rate will be based on the species of fish and other critters you keep.

However, a general rule of thumb is that you should look for filters that can filter through all the water in your aquarium 3 to 4 times each hour.

A 9 to 10-gallon tank, for example, will need a filter than has a flow rate of 30 gallons per hour – or GPH.

Size of Tank

Since HOBs are generally designed for small aquariums, it’s important to keep this mind. Under-filtered tanks can make your fish ill – or even kill them – so it’s important that you’re pairing the right filter with your tank size.

If you’ve got a tank 15-gallons and under, you should do well with a single HOB filter. Tanks up to 30-gallons would need two filters. Beyond that, you should be looking into other types of filters instead.

Media Type

Finally, the filter media or filter pad material in the HOB filter is important. They usually use sponge foam pad media, which is easy to clean and cheap to replace – and only needs replacing occasionally. But you may find a filter with ceramic rings or bio-media instead.

For the best filter for your system, look for sponges covered in activated carbon or other biological media. These will add additional filtration for your aquarium.

Silver dollar Metynnis hypsauchen best hob filter

Reviews of the Best HOB Filters

Now that you know what you’re looking for, and whether or not an HOB filter will work for your aquarium, let’s dive into the best hang on back filter reviews.

How We Chose the Best HOB Filters

To ensure we’re recommending only the best of the best HOB aquarium filters, we took a look at each highly rated filter we could find. We dug through the reviews and information to discover the components necessary for making a good filter. We looked through popular options – like the Aqua Clear Fluval Power Filter and the Tetra HOB Filters – and the lesser known options to find the best HOB aquarium filters with these criteria.

What we looked for were:

  • Flow rates
  • Media type
  • Ease of set up and use
  • Ease of cleaning
  • Durability
  • Any consistent flaws
  • Ratings from real-life users of at least 3.6 or higher (above average)

Below you’ll see the results of our many hours of research combined with personal experience and reviews of each of the HOBs.

EDITOR’S CHOICE

#1. AquaClear

Aqua Clear HOB Fish Tank Filter

If you love the idea of the HOB filter for your aquarium but need to go bigger than a mere 10 to 20 gallons, you’ll love the AquaClear HOB filter.

It’s got all the convenience and ease of use of the smaller HOBs, but the power for tanks up to 110 gallons, if you grab the right model.

There are five different sizes, though, so be sure to select your choice carefully to match your aquarium size.

Here’s the breakdown:

  • Flow rate: 80 to 200 GPH, depending on model
  • Media type: Foam, carbon, biological+
  • Tank size: Up to 110 G, depending on model
  • Durability: High

What We LoveD

The AquaClear offers superior flow rate and power to any other HOB filter on the market. If you have a sensitive nano reef tank or larger freshwater tank and you really want to use an HOB, you’re in luck with this one.

We also love that the AquaClear has multi-stage filtration. Between the biological filtration, mechanical filtration, and chemical filtration media, you won’t find a cleaner, clearer HOB filtered aquarium around.

The fact that this filter is high-powered and budget-friendly is incredible. For the same price as many of the lesser quality models, you can have powerful filtration that will keep your aquarium healthy and happy.

What We Didn’t Love

There are really only two drawbacks we could find for this one.

The first is that there’s not an on/off switch. This isn’t too big of a deal, but it can be annoying at times, especially when you don’t want to unplug it just to move things around in your aquarium. Generally speaking, though, this really isn’t a big deal.

The other potential issue is if you use sand, it may get sucked up into the filter and clog things up. It will make a loud grinding noise that can be really obnoxious, especially in small spaces like a studio apartment. Be sure to use filter floss to keep it clear of sand, or place in an aquarium with gravel substrate instead.

Our Verdict on the AquaClear HOB Filter

All-in-all, this is the best HOB filter out there. We’ve specifically rated it better it for larger aquariums, though, as it may be just a little too powerful for some delicate tanks that need lower water flow rates. For those that can use the power though, this is a top-notch choice.

Be sure to use filter floss to prevent sand from getting sucked up into it or use gravel substrate.

Otherwise, you won’t beat this one anywhere.

>> Tap Here to Read More Reviews and See Today’s Price on Amazon.com <<

BEST SMALL HOB

#2. Marina Slim S10

Marina S10 Power Filter

The Marina Slim S10 is an easy-to-maintain, easy-to-clean, self-priming HOB filter from a well-trusted manufacturer. The filter’s compact and slim, for a nice, neat, tuck away feel filter that doesn’t take away from the aesthetics of your small aquarium. Win-win-win.

Here’s the breakdown:

  • Flow rate: 55 to 92 GPH, depending on model
  • Media type: Ceramic
  • Tank size: 10, 15, or 20 gallons
  • Durability: High

What We LoveD

The Marina Slim S10 is one of our top picks for HOB filters for a reason. Actually, several reasons!

The Marina Slim S10 has a high flow rate for small aquarium use, which means you’ll have a super clean aquarium, as long as you maintain the filter properly.

The filter also uses the more effective ceramic filtration media than most sponge filters, which means even better health benefits for your fish and live plants.

This filter is also super easy to mount, use, and maintain, which means it’s great for any budding aquarist or long-time hobbyist looking for a replacement filter.

What We Didn’t Love

The only real drawback we found for this one is that because the filter cartridges is higher quality, it’s got a higher cost. It’s not the best for people on a super tight budget, unfortunately.

Our Verdict on the Marina Slim S10

Overall, the Marina Slim S10 is among the best HOB filters out there. It’s slim, sleek, and tucks away nicely so that it’s hardly noticeable. It uses ceramic filter media for biological filtration process at its best.

The only potential hang up for it could be the price of replacement media, but unless you’re on a super tight budget, that won’t matter.

>> Tap Here to Read More Reviews and See Today’s Price on Amazon.com <<

Tetra 78004 Whisper IQ Power 60 Gallon Filter

From the ever-popular brand, the Tetra Whisper IQ HOB Power Filter is the quietest hang on fish tank filter on the market. So, if you or someone you live with has an issue with all the noisy equipment associated with aquariums, you’ll want to investigate this one for use in your home.

Here’s the breakdown:

  • Flow rate: Unspecified, but as low as 10 GPH for bettas and high enough for 60+ gallons, depending on model
  • Media type: Activated carbon
  • Tank size: 10 to 60 gallons, depending on model
  • Durability: High

What We Loved

Of course, the first and most obvious thing we love about this filter is the minute volume. The sound is quiet and soothing – if you can hear it at all – and won’t disrupt those with sensitive ears.

The StayClean technology is another huge bonus for this one. It provides easier maintenance for healthier aquariums and their inhabitants.

The adjustable flow control is also fantastic. With the ability to adjust down to as little as 10-gallons per hour, you can use it in sensitive environments, like those for bettas and fragile aquatic plants. Some customers also noted that it’s gentle enough to use in breeder tanks, when turned this low.

We love that you don’t have to prime it, either. Just set it and go.

Finally, this filter has a continuous flushing action that helps prevent debris from building up. Means easier to care for aquariums all around.

What We Didn’t Love

The main issues we noticed with this one were that if you have large fish, they may be able to knock the extension tubes off.

And if you have a heavily stocked aquarium, you’re likely to need extra filter media beyond the standard carbon activated media that comes with this tank.

Our Verdict on the Tetra Whisper IQ

The Tetra Whisper IQ comes from a well-trusted brand that’s been around for 50+ years at this point. The Whisper IQ lives up to the reputation of the company for long-lasting, high-quality products.

It’s super quiet and easy to install, so just about anyone can handle this. It’s not really designed for larger fish or heavily stocked aquariums, and you should make sure you get the size suitable for your aquarium or it won’t have enough power.

Overall, it’s a great little HOB filter that will help to keep your aquarium clean and clear of nitrites and debris.

>> Tap Here to Read More Reviews and See Today’s Price on Amazon.com <<

GREAT FRESHWATER HOB

#4. Zacro

Zacro Aquarium Filter for 20-50 Gal Fish Tank

The Zacro Aquarium Filter with Two Groups Forced Filter Box is a highly efficient aquarium filter that helps remove waste, reduce discoloration and odors, and works well for tanks ranging from 13 to 50 gallons, depending on which of the three models you purchase.

Here’s the breakdown:

  • Flow rate: Up to 200 GPH, depending on model
  • Media type: Any
  • Tank size: 13 to 50 gallons, depending on model
  • Durability: Moderate to high

What We Loved

One of the things we love about the Zacro is that you can choose the media type that you want to use. This is rather unique for most HOB filters, so it’s a great option for anyone with really specific filtration preferences or needs.

We also love that the water inlet pipe is adjustable to fit the size of your tank as needed.

And those lovely two filter boxes can be taken out separately for easier cleaning.

The water flow is super easy to adjust, which is a big plus for new aquarists or those experimenting with new fish keeping stock choices.

The system is also really quiet, which means you can handle it in tighter spaces like bedrooms or studio apartments.

What We Didn’t Love

First, it can be kind of tricky to take apart. So, though it’s easy maintenance otherwise, that makes it a bit sticky.

The second, and biggest challenge for this is that finding replacement media can be hard to come by. But since it will take any form of media, you can choose a different replacement if you can’t find the Zacro option.

Our Verdict on the Zacro Aquarium Filter with Two Groups Forced Filter Box

Overall, the Zacro is a great basic water filter for freshwater tanks up to 50 gallons in size. It’s great for cleaning, sets up easily – though can be a headache to take apart at times – and does a thorough job of getting that water filtered and clear. If you need something simple and affordable, this is a great option.

>> Tap Here to Read More Reviews and See Today’s Price on Amazon.com <<

BEST QUAD FILTRATION HOB

#5. Penn Plax Cascade

Penn Plax Cascade Hang-on Aquarium Filter with Quad Filtration System

Another reliable brand and trustworthy product comes from Penn Plax. The Quad filtration system comes highly recommended from multiple sources, including and especially real-life aquarists. It’s also easy to assemble and can use just about any media you want to adjust to your particular needs.

Here’s the breakdown:

  • Flow rate: Up to 300 GPH
  • Media type: Activated carbon cartridges, uses any
  • Tank size: 7 to 100 gallons
  • Durability: High

What We Loved

For those looking for an easy to assemble filter, you’ve found it. The Penn Plax Cascade is great for beginning hobbyists for this reason.

The filter is also really affordable and a good value for that low price. For those on a tight budget, you’ve found a great option.

The media is easy to replace, the filter has enough room you can put your own choice of media in to work the best for your particular set up.

What We Didn’t Love

There are a couple of things that don’t necessarily run across the board in all circumstances but kept us from putting it at the top of our list.

For one, the intake tube has a large enough opening that some tiny fish can be sucked up and whisked away by the system. We don’t recommend this for breeder tanks or anyone keeping really small fish.

Secondly, the supplied media that comes with the filter isn’t that great. We’d recommend buying a replacement option when you order the filter.

Thirdly, the unit is kind of bulky and not terribly quiet. For those looking for discreet filters, this isn’t your schtick.

Our Verdict on the Penn Plax Cascade Quad Filter

Generally speaking, this is the best hang on back aquarium filter for easy setup and maintenance. It’s got great versatility and is overall super easy to use. Just don’t keep this in small spaces – it runs kind of loud for some folks – and switch out the included media for something better.

>> Tap Here to Read More Reviews and See Today’s Price on Amazon.com <<

Runner Up: The Fluval C Power Filter

Though it doesn’t quite make it into our tip-top choice list for best HOB canister filter, this Fluval HOB filter is still pretty good.

It uses 5-stages of filtration to get things clear and clean in there, and is super easy to maintain. You can use your own choice of filter media, and the tube is telescopic for a custom fit.

Just don’t use with a heavily stocked aquarium, or you’ll have to clean the filter pretty often. 

>> Tap Here to Read More Reviews and See Today’s Price on Amazon.com <<

FAQs on HOB Filters

Can HOB filters be used in saltwater tanks?

Small saltwater tanks – less than 20 gallons – can use HOB filters as their main filtration. Larger aquariums, however, can only use them as secondary filtration.

How do you set up an HOB filter?

After the filter has been removed from the box and thoroughly cleaned, you will insert the filter media into the given media basket in the filter. Replace any lids or caps and place the filter on the back of the aquarium. You will need to manually prime most filters. You do this by filling the filter with aquarium water. Finally, you’ll plug in the filter and let it run.

How do you clean a Hang on back filter?

To clean a HOB filter, you will need to remove the filter from the tank and remove the filter media. From here, you’ll clean the media or replace it, and use some water from the fish tank to clean the media and filter. Use a clean sponge to remove algae and deposits from the housing and rinse off thoroughly with purified water. You’ll then replace the filter media and filter back as they were.

For a more thorough, step-by-step guide, read up from Spruce Pets.

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