You have just bought your first fish tank, or a new aquarium for your pet turtle. Now, you need to figure out what the tank needs. One thing you will need is a filter.
Filters keep the tank clean of waste. Picking the right one may seem difficult if you don’t know what a filtration medium is, or which one is right for you.
This guide will help you pick a hang-on-back (HOB) filter for a fish tank or aquarium. HOB, filters hang on the back of your tank, using less room inside the tank than other filters.
We will look at features like tank size, filtration medium, flow rate, ease of maintenance, and motor type. These are important functions of your filter.
HOB Filter Reviews
Tetra Whisper Power Filter for Aquariums
This HOB filter is quiet and effective. It has easy to refill cartridges for the filters, and can handle up to a 60-gallon tank.
The Tetra Whisper HOB filter is designed to be quiet. It also absorbs odors. Between these features, it makes the tank a more subtle addition to a room, instead of a noisy and smelly one.
This filter is reliable. You only need to change the filters once a month. The cartridges make this easy, and make the filter low-maintenance overall.
The hourly flow rate for this type of filter is more than five times the volume of the tank. This flow rate means that it can filter water quickly and keep the tank clean.
Pros
- The filter has a fast flow rate to filter water quickly.
- Cartridges make it easier to change the filters.
- It is quiet and takes little upkeep.
- It reduces buildup on tank glass.
Cons
- The flow rate is almost too fast, and may not filter as well as well as others.
- It does not handle tanks with volumes higher than 60 gallons.
Aqua Clear Fish Tank Filter
Aqua Clear filters come in sizes that handle 5- to 110-gallon tanks. It has three filters that you can change out at different times to keep good bacteria levels up.
The manufacturer designed this filter to have low operating costs. They made the filtration system so the water has better contact with the filtration medium. This makes the filtration process more efficient.
AquaClear filters handle tanks up to 110 gallons. It can handle larger tanks than almost any other hang-on-back filter. Usually, HOB filters are best for smaller tanks.
This filter has mechanical, biological, and chemical filtration. You only need to change one of the three filters at a time. This means that good bacteria stay in the tank while you clean it.
Pros
- They have more volume than other HOB filters.
- They have three types of filtration.
- Filters can be cleaned at different times so there is always some good bacteria in the tank.
Cons
- If you change each filter at a different time, you will have to change filters more often.
- Some flow rates are low for the size of the tank they are designed for.
Fluval C Power Filter
Fluval C Power filters come in three styles, called C2, C3, and C4. The C4 is designed for larger tanks. The C2 is designed for smaller tanks, and has fewer features.
This filter has 5 stages of filtration, including 2 foam pads for mechanical filtration. It also uses C-nodes to keep up the bacteria that are filtered out by biological filters.
It can filter 153-264 gallons per hour, and can handle tanks up to 70 gallons in volume. This flow rate means it filters water quickly.
The filter has a cleaning indicator that tells when the foam needs to be cleaned. This means you do not need to waste time cleaning the filter unless it actually needs to be cleaned.
Pros
- C-Nodes maintain good bacteria that would be removed by the biological filter otherwise.
- They work on tanks up to 70 gallons in volume.
- They have an indicator to say when filters need cleaning.
Cons
- The flow rate is somewhat high and the filtration may be less effective.
- The chemical filter may need to be cleaned as often as twice a month.
Aqueon QuietFlow LED PRO Aquarium Power Filters
The Aqueon QuietFlow LED Pro Aquarium Power Filter has three filtration mediums. It has features to tell if it needs to be cleaned. It also has high flow rates.
This filter has a high flow rate for an HOB filter. Most filters are good for home use, but this filter meets professional needs for flow rate.
An LED indicator flashes when the cartridges need to be replaced. The cartridges are easy to change out and the indicator means you don’t have to think about changing the filter.
The internal pump means that it is less likely to leak. It also lessens noise from the filter. This keeps the tank from a nuisance, no matter where you put it.
Pros
- This filter does not need to be primed manually.
- The filter has a high flow rate for professional use.
- It has an LED indicator to tell you when to change the cartridges.
Cons
- The high flow rate may mean the water is not filtered as well as it should be.
- It needs specialty filter pads rather than using any medium.
Penn Plax Cascade Hang-on Aquarium Filter
The Penn Plax Cascade Hang-on Aquarium Filter with Quad Filtration system has four types of filtration, including biological, chemical, and mechanical. It has a more effective biological filter than most.
This HOB filter can be used in tanks up to 100 gallons in volume. It has a flow rate of 300 gallons per hour, so it may filter water slower than other filters.
It has a Bio-Falls Quad-Filtration system that works better than other biological filters. It removes more harmful substances than other filters, and keeps aquarium creatures healthier.
The filter has adjustable flow to control how fast it filters water. This means the flow can be lowered for fish and critters that need water with less movement.
Pros
- It can handle a 100-gallon tank, which is larger than most HOB filters can handle.
- It has a more effective biological filter.
- The intake tube length can be changed to fit the tank size.
Cons
- It has a low flow rate relative to tank size when used on larger tanks.
- Smaller versions of the filter do not have biological mediums.
SeaChem Tidal Power Filters
The SeaChem Tidal Power filters work on tanks up to 110 gallons. They have slits in the lid to increase the oxygen level in the water.
This filter has a surface skimmer to clean debris from the surface. This helps keep the top of the tank clear of oil, algae, and other things that need to be removed.
It has extra ventilation slots in the lid to increase gas exchange. This means the water has more oxygen in it for the creatures to breathe.
The filter has an adjustable intake and flow rate. That means you can set it to draw any amount of water from any point in the tank. This makes an ideal environment for any creature.
Pros
- It works in saltwater or freshwater tanks.
- Both the flow rate and intake pipe can be adjusted.
- It will alert you when a filter needs cleaning.
- It works on tanks up to 110 gallons.
Cons
- The surface skimmer can disturb the water more and upset fish that tend to stay near the top of the tank.
- They are louder than other HOB filters.
MarineLand Penguin
The MarineLand Penguin filters tanks up to 70 gallons. It uses three different filtration mediums. This includes a patented biological filtration medium that is more effective than most.
This filter has a rotating bio wheel. This is a great biological filter that keeps healthy bacteria to filter toxins. This keeps the tank clean.
The filter uses convenient cartridges for the filtration medium. These cartridges can be changed out to clean the filter. This makes it simple and easy to keep the filter clean.
It can handle tanks from 20-70 gallons in volume and has a flow rate of 150-350 gallons. This is a good flow rate. This is on the high side for an HOB filter.
Pros
- It has a high flow rate to filter water fast.
- It has convenient cartridges for changing out filtration mediums.
- It has high quality biological filtration.
- It has all three types of filtration mediums.
Cons
- The flow rate may mean the water is not filtered as well as it could be.
- The filter is often louder than most and may be bothersome.
Marina Power Filter
The Marine Power filter is a thin, easy-to-use HOB filter that self-primes. It is adjustable and quiet. The filter uses biological filtration only.
This filter works on tanks of up to 20 gallons in volume. It has an adjustable flow control to change how fast it filters water. This helps adjust for different sized tanks and different inhabitants.
The filter is self-priming. Many filters need to be filled with water before they can start. This filter does not need to be filled, and starts on its own.
The motor is submerged so it runs quietly. It is thin and has cartridges for cleaning the filtration medium. This makes it convenient and easy to use.
Pros
- It is easy to clean.
- It is self-priming and can start as soon as it is plugged in.
- The flow control can be adjusted for the tank size and type of fish.
Cons
- It does not have mechanical and chemical filtration to help with better cleaning.
- It only works on tanks with volumes that are 20 gallons or less.
EHEIM Liberty 200 Hang On Filter
The EHEIM Liberty 200 HOB Filter is a reliable and quiet filter for smaller tanks. It is great for nurseries or quarantine tanks. The simple setup makes it good for new aquarium owners.
This filter has biological, mechanical, and chemical filtration. It has a large filter sponge that lasts longer than others. The large sponge also improves the quality of the biological filter.
It can be used with a cellular foam cartridge that is good for quarantine or breeding tanks. The adjustable flow lets you adjust flow for the fish in the tank.
New fish owners can use this filter, since it is simple to install and use. It is quiet so it there is little to no noise to bother you.
Pros
- You can change the flow rate as needed.
- It is simple for people who are new at owning aquatic creatures.
- It has a large sponge filter that is long-lasting and effective.
- It is reliable.
Cons
- It only works on tanks smaller than 50 gallons.
- It has a short intake hose.
- It is not overly popular, and parts may be hard to find.
GRECH CBG-500 5W UV Sterilizer Hang-On Back Filter
The Grech CBG-500 5W UV Sterilizer Hang-On Back Filter is for tanks up to 50 gallons. It has a surface skimmer to keep the surface clean, and uses a 5W UV Sterilizer.
This HOB filter has only biological and mechanical filtration. The mechanical filtration gets debris out of the tank. Biological filtration keeps up healthy bacteria that clear toxins out of the water.
The filter has a surface skimmer to clean the surface of the water. It also has a 5W UV Sterilizer that helps get rid of algae and bacteria. These features keep the tank cleaner.
The flow rate can be adjusted for different needs. Higher flow rate increases oxygen in water, but if the rate is too high, the filter will not work as well.
Pros
- It works in saltwater or freshwater.
- The flow rate can be changed to suit you and the creatures living in it.
- The surface skimmer gets rid of films on the water.
Cons
- This filter only works on tanks from 10 to 50 gallons in volume.
- The surface skimmer may upset creatures that like to stay near the surface.
How to Pick an HOB Filter?
- Number of Filtration Stages: Companies advertise the number of filtration stages for products. These can be biological, chemical, or mechanical filtration. In truth, the filtration medium is more important for good cleaning than the number of stages.
- Filtration Media: Biological filtration is the most important type of filtration, but it is good to have all three. Some also have a bio wheel that keeps a healthy bacteria balance when you have a biological filter. Sponges are good because they can provide both mechanical and biological filtration.
- Flow Rate: Flow rate is basically how fast the filter cleans the water. In general, the flow rate in gallons per hour should be at least 4-5 times the number of gallons in the tank. Higher flow rate means it filters faster, but if it is too fast, it will not have time to filter properly.
- Tank Size: The filter should be designed for the size tank you have. You can get away with a filter designed for a larger tank, but it may upset the fish by causing a faster current. More powerful filters increase aeration but also increase how fast the water in the tank moves.
- Motor: Older tanks had removeable motors, but most new ones have incorporated motors. Cleaning a removable motor can be a hassle. Attached motors do not need to be removed and cleaned.
- Ease of Maintenance: Look for a filter that will be easy to maintain. Some filters will have a cover on the impeller. This cover is good because the filter will not have to be cleaned as often.
How to Install an HOB Filter?
One great thing about HOB filters is that the name tells you where to install them. They are simpler than most filters. This section describes the installation process.
- Add the filter media first. This will be a ceramic ring, bio-ball, sponge, or other medium. In many cases, there will be multiple media that you will have to place in separate compartments.
- Put the filter in place. As we know, the filter hangs on the back of the tank. If the tank has a lid, there will likely be a clear spot to hang the filter. Otherwise, it can go anywhere on the tank lip.
- Prime the filter. To get the filter to start, you may need to fill it with water, also known as priming it. Some filters prime themselves, so check the instructions on your filter.
- Fill the Tank. If you have not filled the tank yet, do so before plugging in the filter. Make sure the water is above the intake for the filter so the filter can take in and clean water.
- Plug it in. You are ready to plug the filter in. It should turn on right away without further setup. Avoid getting water on the plug or outlet, and make sure the plug and outlet are completely dry before you plug it in.
How to Maintain Your HOB Filter?
Cleaning
Once it is installed, your filter will need some maintenance. The main thing you will need to do is clean the filter every month or so. Make sure the filter is unplugged before cleaning.
Rinse any filtration mediums in water from the tank to avoid killing needed bacteria. Clean the impeller and scrub out any tubes. When you reinstall the filter, fill it with old aquarium water rather than tapwater, to avoid killing bacteria.
Fixing a Loud or Broken Filter
If the filter starts to run loudly, it may be a sign that it is about to break. While fixing the filter, make sure to clean any part you expose as you go. Sometimes cleaning more thoroughly is all you need to do.
To fix a loud or stopped filter, take the impeller out and clean it. Then, pull on it to see if the top and bottom parts separate. If they do, it is broken and needs replacing.
Next, check to see if the cylinder on the impeller is broken. This cylinder is a magnet, and if you see any lines on it, it is cracked and needs replacing.
After checking the impeller, remove the shaft that the impeller is attached to. You may need pliers to do so.
The middle part of the shaft gets thinner over time. If the middle part of the shaft is noticeably thinner than the rest, it should be replaced. The new shaft will be the same thickness throughout.
Next, clean and replace any parts. Make sure that the shaft is in solidly. If the shaft will not go back in solidly, the whole motor needs to be replaced.
Frequently Asked Questions About HOB Filters
What is the Difference Between HOB and Other Filters? HOB filters are hang-on-back filters, meaning they hang on the back of the tank. This means most of the filter is outside the tank, rather than taking up underwater living space. These filters are usually lower capacity than others.
What is an Impeller? An impeller is a motor part. The visible part of it will be shaped like a white star. When you pull it out of the motor, it will have a black cylinder attached to it.
Can HOB Filters be Used in Saltwater Tanks? Yes, they can, but they should only be the main filter for tanks under 15 gallons. If you use a HOB filter in a saltwater tank, you will need to research a different filter medium than the one provided. The mediums designed for freshwater tanks will harm saltwater environments.
How Do HOB Filters Work? HOB filters hang on the back of your aquarium. They take in water and run it through a filtration medium to clean it. The water is then sent back to the tank.
Why Should I Use a HOB Filter and Not a Canister Filter? HOB filters are small and take up less space in the tank. They may store less filter medium, but unless you have delicate fish, they work fine. HOB filters work better for smaller tanks in general, but they are easier to clean, install, and maintain.
What is a Filtration Medium? Filtration media are what the water filters through inside the filter. The three types of media are biological, chemical, and mechanical. Each one filters water differently.
Conclusion
When you choose your HOB filter, make sure it is the right size and flow rate for your tank. The GPH should be at least 4 times as much as the gallons in the tank.
Think about how you will use the filter. It is essential to pick the right flow rate and filtration medium for the creatures the tank will house.
Make sure to have our buying guide on hand, and head over to amazon.com now using the links we gave for each filter. Is there anything missing from our guide? Let us know.
