Back in the days, undergravel filters or UGFs were a thing. They were basically filters that use air pressure and suck up dirt from below using tubes. Undergravel filters were hip and cool before since they do not add a lot of obstruction to your fish.
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If you just want a scenic view of your fish tank, you may be looking for the best undergravel filter. Fortunately, we have some picks here just for you, as well as tips on how to choose the best one in the market.
Surely, there are different models depending on your tank size, but mainly Penn Plax and Lee’s are the only two best-known manufacturers of undergravel filters today. They make quality filters depending on the size of your aquarium and the fish that you have.
Top 5 Best Undergravel Filter System
Here are our top picks for the best undergravel filter:
Penn Plax 40/50 Undergravel Filter
As an undergravel filter that can fit 40-gallon up to 50-gallon tanks, this one consists of 4 filter plates, each measuring 11.5 x 11.5 inches, and lift tubes that measure 1 inch each.
These tubes can be adjusted depending on your aquarium setup and where you want to direct the outward flow.
Since it has 2 carbon filter cartridges, it can possibly remove odors in your tank as well. It can be easy to set up and can be used regardless if you have a freshwater or saltwater tank.
You can also buy the carbon cartridges separately when you need to replace them in about 6 to 8 weeks of time (average use).
Things We Liked
- Easy to set up
- Large tubes at 1 inch each
- The tubes can be adjusted
- Includes carbon filter cartridges for odor-reduction
- Okay for freshwater or saltwater tanks
Things We Didn’t Like
- The tubes can get dirty quickly (may change depending on usage)
Lee’s 10 Premium Undergravel Filter
As a UGF, this filter has a size of 10 x 20 inches and have larger plate sizes.
This can keep them tied to the bottom of the tank even better than with those that have smaller plate numbers and sizes.
It also holds the filter steady on the ground. Special plastic has been used on the plates so it can avoid cracking on splitting.
The filter is okay to use for a cichlid, goldfish, bottom feeders, bettas, and the like.
You can also use it for a turtle tank due to its design, although it does require the pipes to be cut down so that the charcoal filters will work. The filter is applicable for tanks as low as 10 gallons in size.
Things We Liked
- Can be used in smaller aquariums
- Larger plate design
- Quality plastic material
- Okay for betta fish
- Can be used with power filters
- Comes with carbon cartridges
Things We Didn’t Like
- Can be difficult to put together on existing tanks (with the existing rocks)
Penn Plax 29/20 Under Gravel Filter System
Made for aquariums up to 29 gallons in size, this one comes with an adjustable lift tube so that you can position it in the right direction to avoid the fish getting blown away.
Its tube size is 1 inch so it can be big enough to avoid clogging. What’s more, filter cartridges made of carbon are included in the pack.
This filter combines biological and chemical filtration and is quite easy to set up. It comes with all equipment needed, such as air stones, filter plates, and the like.
The plates are also easy to put together due to the secure locking mechanism.
Things We Liked
- Large 1-inch tubes
- Adjustable lift tubes
- Comes with carbon filters
- Easy-snap plates
- A complete setup
Things We Didn’t Like
- Some tube prongs could arrive damaged (depending on delivery)
Lee’s 125/135 Premium Undergravel Filter
This UGF has a size of 18 x 72 inches and has larger plates than most filters out there.
This can make it easy to set up, to connect, and it adds weight so that the UGF stays on the ground.
It also comes with free carbon cartridges inside for reducing fish odor.
Okay to use for cichlid, goldfish, bettas, and the like, it has a multi-level design for the plates for added thorough cleaning.
The powerheads included work just fine for each plate. Since it has a good amount of power and area, you can use it for bigger tanks, such as those up to 180 gallons.
Things We Liked
- Safe for betta fish
- Large plates
- Easy to connect together
- Stays on the ground
- Comes with carbon cartridges
- Good for bigger tanks
Things We Didn’t Like
- Could be too tall for some low-designed tanks
Lee’s 40/55 Premium Undergravel Filter
This one has been designed for those with 40 to 55 gallons, much like our Penn Plax pick, but it’s from Lee’s.
It measures 12 x 48 inches and has added UGF plates that keep it sticking to the ground. If you are a saltwater fish keeper, this can be a good startup filter.
Since it has a multi-level plate design with materials such as special quality plastic, it won’t crack easily and it can be simple to put together.
It also comes with active carbon cartridges, which can help in reducing bad odor inside your tank, especially if you haven’t cleaned it for a while.
Things We Liked
- Great water distribution
- May work for naughty cichlids that dig up gravel
- Has a high-quality plastic bedding
- Comes with 4 active carbon cartridges
- Comes with extra filter tubes
- Includes caps for the ports
Things We Didn’t Like
- Could be too tall for some low-designed tanks
Things to Consider Before You Buy
In choosing the best undergravel filter, here are some criteria:
What are the benefits of an undergravel filter?
There can be many benefits to buying an undergravel filter, such as the following:
- They tend to last longer. Since they have no moving parts and aren’t mechanical, you can expect them to last for many years without cracking and the like. They just sit there!
- Your fish (and plants) have more room to breathe. UGFs don’t suffocate fish, unlike other bulky filters.
- You can put the gravel you have to use. Since undergravel filters work under your gravel (hence the name), you can use your very own gravel or substrate to act as the filtering mechanism. That means no more going to the store and buying HOB filter media!
- Ease of setup. UGFs are generally easier to set up than most HOBs and canister filters.
- Biological filtering. They also deploy good bacteria to eat up the algae on your tank walls.
- Can be used as a supplemental filter. If you have any power filter, this can act as a supplemental one.
- They aren’t very expensive. UGFs are available in your local pet shop, typically at a low price.
What problems could I encounter with an undergravel filter?
You may encounter the following problems if you do keep a UGF:
- Cleaning problems. Vacuuming the substrate is kind of mandatory since if you don’t do that, the bacteria and other dirt will stay and it will not be as effective as it used to be.
- Gravel-diggers. If you have fish or other species that like to dig into your substrate or gravel then that’s going to be a problem. This may not be your best option if you have burrowers.
- They work best only on new aquariums. If you already have your substrate laid down then putting an undergravel filter can be a bigger challenge.
What kind of tank works well with an undergravel filter?
A tank that is quite new will work best with a UGF. If you already have gravel or substrate, as well as plants in your tank, it would be difficult to install it.
Other than that, tanks that will have more fish and plants may benefit more from an undergravel filter. If you have a tank in which space gets cramped, the UGF can help add aesthetics to it.
How do I choose the best undergravel filter?
A UGF that’s best for your needs should have the following:
- Adjustable tubes to direct the flow specifically.
- Large tubes for avoiding clogging.
- The right size for your tank capacity, so you need to measure your tank first.
- Quality plating material to avoid cracking and floating out of place.
- Easy to install with all equipment and items included in the pack.
Conclusion
We chose the Penn Plax 40/50 Undergravel Filter for the best undergravel filter because of its ease of setting up, large tubes at 1 inch each (which cause a better flow), and the fact that the tubes can be adjusted makes it convenient. It even includes carbon filter cartridges for odor-reduction and the design is okay for freshwater or saltwater tanks.
While the tubes can get dirty quickly, this really depends upon your usage, the number of fish you have, and other factors.
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