- Updated Feb 22, 2020
- Writen by Editorial Staff
6 Best HOB (Hang-On-Back) Filters for Small Aquariums
- Updated Nov 20, 2018
- Writen by Editorial Staff
HOB means Hang on Back, referring to filters that are hung on the backside of aquariums. As compared to other types of filters, HOB units have the advantage of easy accessibility to the filtration media for quick replacement, which results in quick and easy maintenance.
Therefore, if you want to have an easy time maintaining your fish tank, it is vital that you buy the best HOB filter. This article gives you an in-depth review of the best ones in the market so that you can have an easier time picking the most suitable one for your tank.
- 6 Best HOB Filters – Reviews
- HOB vs. Canister Filters
- How to Buy the Best HOB Filters
6 Best HOB Filters – Reviews
1. Aqua Clear A620A1 (Best Overall HOB Filter)
2. Marineland PF0350B (Best Budget HOB Filter)
3. Fluval C4 (Best HOB Filter for Saltwater Tanks)
4. Penn Plax Cascade 300 (HOB Filter with Adjustable Flow Control)
5. Aqueon 100106117 (HOB Filter with 5-Stage Filtration)
6. Tetra 26313 (Silent HOB Filter)
1. Aqua Clear A620A1
(Best Overall HOB Filter)
2. Marineland PF0350B
(Best Budget HOB Filter)
3. Fluval C4
(Best HOB Filter for Saltwater Tanks)
4. Penn Plax Cascade 300
(HOB Filter with Adjustable Flow Control)
5. Aqueon 100106117
(HOB Filter with 5-Stage Filtration)
6. Tetra 26313
(Silent HOB Filter)
1. Aqua Clear A620A1 – Best Overall HOB Filter
- Available for: 60 – 110 gallons
- Flow rate: 500 GPH
- Filtration stage: 3 stage
Aqua Clear’s product is one of the best HOB filters for aquariums because it has a very large filtration compartment.
This section is big enough to house up to 7 times more media volume as compared to other filters of a similar size. This means that it can do a better job at filtration because of exposure to the extra media volume.
Additionally, the unit’s flow control is adjustable and can be reduced by up to 50% without damaging the motor or impeller.
That said, you get a very fast 500 GPH max flow rate and the flow adjustment increases the water's contact period with the filtration media for thorough purification.
In terms of operations, the unit requires priming before use after which the pump takes over to power a 3-stage filtration system. It consists of a foam for mechanical filtration, activated carbon for chemical filtration and bio-max ceramic rings for biological filtration.
What stands out about this setup though is that it has a cycle guard system, which ensures significant amounts of beneficial bacteria remain as you change the depleted media. This is achieved by requiring only one of the three media to be changed at a time.
The carbon filter needs a replacement every month, foam filter every two months and the bio-max every three months. This arrangement ensures that beneficial bacteria are not depleted as you maintain your unit.
2. Marineland PF0350B – Best Budget HOB Filter
- Available for: 50 – 70 gallons
- Flow rate: 350 GPH
- Filtration stage: 3 stage
Marineland’s Penguin filter is the most affordable product in this review but this does not mean it is a low-quality unit.
For starters, it has a 3-stage filtration system, with the revolutionary bio-wheel technology for biological filtration. This wheel is proven as one of the best methods of dealing with nitrites and toxic ammonia from the aquarium’s water.
Mechanical and biological filtration is carried out by two rite-size C filter cartridges to provide a complete water purification cycle.
Setting up the unit is quite easy. In fact, no set up is required before first use because the filter comes fully assembled. You just have to attach it to the tank wall and prime it before plugging in the power cord.
The Penguin is also easy to maintain because it requires a general clean-up and filter cartridge change approximately every month. However, it is important to maintain the same bio-wheel after this cleanup so at to reuse the beneficial bacteria that had already grown inside it.
That said, if you find this wheel broken or torn, you might have to change it and this might make you lose a lot in terms of biological filtration. The good thing though is that these bacteria grow back in a short time.
3. Fluval C4 – Best HOB Filter for Saltwater Tanks
- Available for: 40 – 70 gallons
- Flow rate: 264 GPH
- Filtration stage: 5 stage
Saltwater aquariums usually require more powerful filtration systems and Fluval’s C series filters are perfect for the job because they have a 5-stage filtration system, which does some thorough purification.
The first and second stages in this process do the mechanical filtration using a foam pad. A porous foam gets rid of large particles in step 1 and a dense foam captures fine debris in step 2.
Chemical filtration is done in stage 3 using an activated carbon insert, which gets rid of the bad odor, discolorations, and impurities.
A biological bio-screen is next in line for removing any debris and spreads out the water before passing it onto the final stage, which contains beneficial bacteria in biological C-Nodes for eliminating ammonia and nitrites.
For easy installation, a clip is included and this also makes it easy to maintain because you can easily unhung the piece for cleaning or changing the filtration media.
A cleaning indicator is built into the unit to show you when the polyfoam needs to be rinsed and during this time, you should check and replace some of the other media.
4. Penn Plax Cascade 300 – HOB Filter with Adjustable Flow Control
- Available for: 55 – 100 gallons
- Flow rate: 300 GPH
- Filtration stage: 4 stage
Penn Plax’s Cascade filter features an adjustable flow control knob that enables you to reduce or increase the filtration speed as required.
Slower flow rates are especially good for thorough water cleaning and coupled with the Cascade’s 4 stage filtration system, this results in crystal clear waters for a 55 – 100-gallon tank.
Other than that, the unit is designed to be very quiet, which causes little or no interruption to your peace after a long day at work. It also requires no priming, making it very convenient to use as compared to other HOB filters.
You also get an adjustable intake tube and a self-leveling case, which ensures that the filter is kept level when mounted on an aquarium wall.
5. Aqueon 100106117 – HOB Filter with 5-Stage Filtration
- Available for: Up to 50 gallons
- Flow rate: 250 GPH
- Filtration stage: 5 stage
Aqueon’s QuietFlow is relatively affordable HOB filter that has a powerful 5 stage filtration system. This consists of a dense floss for mechanical filtration, activated carbon for chemical filtration and a patented bio-holster for biological filtration.
The fourth stage consists of a bio-media grid for removing any remaining toxins while also oxygenating the water and lastly, a specialty filter pad for the final water treatment. This design combines a filter and an air pump into one, making the QuietFlow a very versatile product.
In terms of design, this filter has an internal pump, which is submerged in the water when the unit is installed and operational.
This makes it very quiet with a continuous suction of water and few, if not zero, chances of leaks. Additionally, a submerged pump does not require priming on restarting the filter.
All these features make QuietFlow one of the best hang-on-back filters available. However, the unit’s flow rate is not adjustable, instead, it is set at the most suitable speed for supporting its filtration process.
6. Tetra 26313 – Silent HOB Filter
- Available for: 45 – 70 gallons
- Flow rate: 340 GPH
- Filtration stage: 3 stage
As the name suggests, Tetra’s Whisper filter is also a very quiet unit and this is because the motor goes into the water once the unit is installed. Water dampens the noise and vibrations and the other benefit of this design is that it does not require priming before use.
After setting off, time strip technology is used to time the carbon filtration cartridges so that you can always remember to change them before they affect the filtration process. This means that your filter will always be effective since the media “expiry” will always be in check.
The unit uses large filter cartridges and these increase the surface area for contact with the water. When the expiry date comes, maintaining the Whisper is quite easy because it has an easy access door at its top for quick changes of the filter cartridges.
However, it is important to note that this filter is not recommended for use in saltwater tanks.
HOB vs. Canister Filters
Hang on back and canister filters are the most popular types of filtration systems used in maintaining aquariums.
HOB filters: usually cheaper and easy to use as compared to canisters but are less powerful. However, the most important differences are in the internal working mechanisms between the two.
For the filtration stages, standard floss/ foam is used for mechanical filtration while activated carbon and bio rings or wheels are used for chemical and biological filtration respectively.
The biggest issue with this design is the mechanical floss, which gets clogged up really easily and therefore, must be cleaned frequently.
Also, by being small in size and disruptive of the water surface, HOB filters allow salt to penetrate through their inner workings, which means that a bigger maintenance task is required if you use the unit on a saltwater tank.
Canister filters: on the other hand, can be quite big because they are set up outside of the tank. This means that they can house superior filtration media for the various filtration stages and at a big quantity.
These units can also be equipped with UV light for filtering out algae and other microorganisms because they can be built big to accommodate such features.
However, canister filters require more effort to maintain. First of all, they have a lot of components, which means they require more work to set up. They may also require more filtration media for replacement purposes because they are usually big in size.
Verdict: Canister filters generally are the best types but are most suitable for large tanks and work very well in purifying saltwater aquariums. However, if you have a small fish tank and you are on a budget, the best option for you is a hang on back filter.
How to Buy the Best HOB Filters
A filter’s compatibility is usually considered due to many factors.
First, is the tank size. All HOB filters are rated based on the aquarium tank size that they can be comfortably used on.
For instance, a filter that is rated for a 45 – 70-gallon aquarium (such as Tetra's 26313) should be used to clean tanks of up to 70 gallons in capacity, although it would be too powerful for smaller that 45 gallon tanks.
However, the unit should not be used for any aquarium that is greater than 70 gallons in capacity because it will not be powerful enough to clean up the waters, especially if there are a lot of livestock inside.
Another important thing to consider when it comes to compatibility is salinity. There are some HOB filters that are capable of cleaning both salt and freshwater while others can only deal with freshwater.
2. Flow Rate
The flow rate of a filter basically shows you the speed at which the unit functions in purifying your tank’s water.
The higher the flow rate (like the 500 GPH in Aqua Clear's A620A1), the better the filter because it can turn over the whole volume of water in the shortest time possible.
Other that the flow rate, another important feature to look for is adjustable flow control, which is featured in Penn Plax's Cascade 300.
With this, you will be able to reduce or increase the flow rate as required, giving you more control over the filtration process.
Filtration is the main purpose of a filter. It is usually given in terms of stages, with stage 1 being for mechanical filtration, stage 2 for chemical filtration and stage 3 for biological filtration.
These are usually enough for the filter to be effective at maintaining your tank but they should be large enough so as to provide a big surface area for filtration.
You might notice that other HOB filters have more than 3 stages of filtration, which provides even better filtration. However, the more the number of stages, the more the strain that they apply to the pump.
This is because the pump is left with the task of forcing water through more layers of media and a noticeable thing you will see in such systems is a relatively low flow rate due to this strain. The result of this is high power consumption.
Otherwise, stick to 3-stage units, with Marineland's PF0350B being an ideal example.
Although maintaining HOB filters is much easier as compared to other types of filters, they still need their own form of care for instance in replacing the filtration media monthly or quarterly, depending on the manufacturer’s specifications.
Because of this, the best HOB filter for fish tanks needs to be easy to dismantle, clean, change the filtration media and put back together so that you can have an easier time doing maintenance. For this, check out Marineland's PF0350B.
Having been designed for indoor use, HOB filters should operate silently so as to minimize on noise disturbance.
Considering Tetra's 26313, its pump is submerged in water so that the noise and vibrations can be dampened.
HOB filters are very important to have, especially if you own a small fish tank. They are affordable, yet they carry out the task of filtration really well.
With that in mind, Aqua Clear's A620A1 emerges as the overall best HOB filter because it has a fast, adjustable flow rate that can cater to a wide variety of tanks and large media volume that rivals the performance of the 5-stage filters.
However, check out Fluval's C4 if you have a saltwater tank.