Also called the heart of the tank, the filter is an essential component that keeps the aquarium balanced and healthy.
That said, it comes in many different types and sizes, and it’s up to you to find the suitable model for your tank.
For an effective, reliable, and budget-friendly filtration system, you need the best under gravel fish tank filter.
We tried and tested several models to come up with this list of the top five.
Best Under Gravel Fish Tank Filter Reviews
1. Penn-Plax Clear-Free Under Gravel Filter
Penn-Plax is one of the most reliable brands in the aquarium accessory market.
It focuses on top-notch aquatic research and development to ensure you can provide your fish with a safe and healthy home.
Among Penn-Plax’s proud creations is the Clear-Free Under Gravel Filter.
Each of the two filter plates measures 11.25 (W) by 11.25 (D). Together, they become 45 inches wide. The lift tubes are adjustable from 13.25 to 16.5 inches.
The Clear-Free Under Gravel Filter is the perfect UGF system for you if you have a 40- to 50-gallon fish tank.
You can use this under-gravel filter regardless if you’re building a freshwater or saltwater tank. The materials are durable, and the system is simple to set up and maintain.
The Penn-Plax Clear-Free Premium is designed to help your aquarium maintain a clean and tidy appearance.
While it is air-operated, it is worth noting that the package does not include an air pump.
Instead, it comes with two filter plates, lifting tubes, carbon cartridges, and air stones—all working together to circulate crystal-clear water throughout the tank.
Compared to other systems, you will notice that the lifting tubes are not only extra-large but also easily adjustable.
Thanks to this, you can use them to create a customized filtration setup that suits your tank.
If you’re new to fishkeeping, you probably don’t know about the sulfurous odor that occasionally afflicts UGFs.
To address this, the Penn-Plax Clear-Free Premium comes with two carbon filter cartridges to help keep the water pure and odor-free.
You can expect these cartridges to last up to six to eight weeks; by then, you’ll find that they are easy to replace.
In fact, inserting new cartridges in place would only take a few minutes.
Another thing to like about the Penn-Plax Clear-Free Premium is the fact that it is quick and easy to put together.
Assembling the plates and filter tubes won’t require special tools, and connecting them to the air pump is not rocket science.
Even if it’s your first time setting up your own tank, you will find the included assembly instructions easy to follow.
- Easy to install, even for beginners
- Comes at a very reasonable price
- Includes carbon cartridges and air stones
- Ideal for saltwater and freshwater aquariums
- Aerates the tank at the same time
- Requires little maintenance
- Does not include an air pump
- Filter plate connectors are weak and break easily
2. Lee’s 13210 Original Under Gravel Filter
For many years, Lee’s has been among the trusted brands in the aquarium accessories and filtration systems industry.
With this much experience in fishkeeping, you can rely on its products to provide effective filtration solutions.
One of Lee’s most sought-after creations is the 13210 Original Under Gravel Filter, probably because of its exceptional multi-level plate design.
Measuring 10.5 x 1.5 x 9.5 inches, this particular model is perfect for 10-gallon tanks.
So, if you are yet to upgrade to bigger aquariums, the Lee’s 13210 is the right UGF for you.
Under-gravel filters use your tank’s gravel substrate as a bio-filtering surface.
At the same time, they also add oxygen to the tank by recirculating the water up to the uplift tubes and down through the media.
They are a necessary component that all fish tanks need, which is why it’s a good thing they come at budget-friendly prices.
This is precisely what you can expect to get when you purchase the Lee’s 13210 Original Under Gravel Filter.
Like the Penn-Plax Clear-Free Premium, it has a high-quality plastic construction that won’t split or break easily.
Even after months of use, the filter plates will remain unaffected by the weight of the water and the substrate.
Because it has sturdy plastic components, you will find no problems using it with a freshwater or saltwater tank.
It’s also possible to use this under-gravel filter if you’d rather have a flow-through tank setup.
Setting up this UGF is hassle-free because all the components snap into place.
You will receive two filter plates you can put together for easy installation and two height-adjustable uplift tubes one inch in diameter.
For a 10-gallon tank, this setup should be enough to ensure proper water circulation across the filter plates.
The kit even includes a discard-A-stone, airline tubing, and fish-saver elbow so that you can set up your aquarium filter however you want.
- Sturdy plastic construction
- Assembles quickly and easily
- Includes an air stone
- The uplift tubes are adjustable
- For budget-friendly builds
- Only for small tanks
- Air pump is sold separately
3. Lee’s Premium Under Gravel Filter
If you have a bigger tank and a bigger budget, you might want to get the Lee’s Premium 20L/29 Under Gravel Filter instead.
Not only does it have a bigger filter plate at 12 by 30 inches, but it also looks more well-made, hence the “Premium” tag in the name.
It would be the perfect UGF system for 20-liter aquariums.
The Lee’s Premium 20L/29 is a biological filtration system that boasts bigger, multi-level plates.
For this reason, you will only need fewer filter plates to have an extensive enough UGF for a 20-liter tank.
Unlike the first two options, this set comes with a single filter plate, so you must make sure it will fit the dimensions of your tank.
Made from a special type of plastic, the filter plate is more durable than cheaper under-gravel filters.
More importantly, you’d be able to use it both in freshwater and saltwater aquariums without any worries.
Like the previous option, the Lee’s Premium 20L/29 comes with two one-inch-diameter uplift tubes to allow superior water circulation.
These riser tubes are equipped with gravel shields to prevent the substrate from being sucked into them.
Once installed, you will notice the big under-gravel filter plates cycle the tank quickly, especially compared to canister or box filters.
This means you can transfer your fish into their new homes much quicker.
You can also choose to set it up with a flow-through arrangement if that’s what you prefer.
Note that the package doesn’t include an air pump, so you will have to use an existing one or purchase a new device.
That said, you will get Lee’s very own Discard-A-Stone, a disposable air diffuser you can reuse by simply replacing the insert.
- Unique, single-plate design
- Larger plate size
- Comes with an aeration device
- Quick and hassle-free installation
- Robust plastic construction
- Low maintenance requirements
- Air pump not supplied
4. CORISRX D62140 Under Gravel Filtration
The CORISRX D62140 is a good-quality under-gravel filtration system that works with both saltwater and freshwater builds.
It is big enough to fit 55-gallon tanks, and you can pair it with mechanical and canister filters.
You will receive three 16.6cm PVC tubes, 27 16.6cm circular bar tubes, and seven pieces of L-shaped connector joints.
Even at first glance, you will notice how different this UGF system is compared to other options on this list.
Instead of a filter plate, it has a bottom circular bar design that you also bury underneath your chosen substrate.
With a surface area measuring 45.3 by 9.6 inches, the CORISRX D62140 is ideal for 48-inch fish tanks.
That said, you can assemble the tubes and joints however you like to achieve a perfect fit based on the dimensions of your tank.
Even if you have a smaller fish tank now but plan on upgrading in the future, you can use this same under-gravel filter.
As mentioned, it would work best if you pair it up with a mechanical filtering system, especially one that uses activated carbon cartridges.
This combination guarantees that water circulation is improved and that every inch of your tank is free of ammonia and other potentially hazardous contaminants.
At the same time, it sucks in all the beneficial bio-bacteria, allowing them to flourish under the substrate and nourishing your plants.
Surprisingly enough, it also helps neutralize the tank’s water temperature.
Once installed, the CORISRX D62140’s dual filtration power ensures your tank gets optimal filtration and crystal-clear water for an extended period.
Simply connect it to a powerhead, and you’re good to go. For an even more advanced setup, you can also connect it to a rain bar unit and a canister filter.
While the system performs incredibly well, beginners in the fishkeeping hobby might find it challenging to set up.
- Easily adjustable to fit tanks of different sizes
- Suitable for freshwater and saltwater builds
- Accommodates up to 55-gallon tanks
- Improves water circulation
- Neutralizes water temperature
- Not as easy to assemble as filter plates
5. XMHF Under Gravel Filter
Last on our list of the best under gravel fish tank filters is this simple yet functional filtration system from XMHF.
Like the others, it is made of durable plastic, so you can expect it to last a long time.
Each package contains 24 pieces of small filter boards measuring 5.5 x 2.8 x 0.5 inches. You will also get a 12.6-inch lift tube with a one-inch diameter and a 0.2-inch-diameter air hose line.
To help aerate the tank, the kit includes an air stone that is one by 0.6 inches.
The XMHF Under Gravel Filter is perhaps one of the most versatile filtration systems you’ll come across.
You can effortlessly pair it with an air pump and a canister filter.
Since it comes with 24 filter boards, you’d be able to set up a multi-layer filter base to ensure optimal filtration.
Even better, this also means it can adapt to various tank sizes.
The premium-quality plastic build guarantees it won’t split or crack, whether you decide to build a freshwater or saltwater tank. The plates are also easy to clean.
Despite having too many parts, you won’t have a problem setting it up. That said, you will need to purchase a pump or powerhead separately.
The beauty of this UGF is in its simplicity. Even with its straightforward design, you’d be able to achieve a dual filtration setup.
Overall, you will find that it’s a reliable tank filter that is easy to install and clean.
- Quick and easy assembly
- Made of solid and durable plastic
- Perfect for budget builds
- Can be made to fit small to large tanks
- Installation requires no tools
- Includes an air stone
- Comes with a single riser tube
Which Is the Best Aquarium Filter?
Installing an under-gravel filter will help ensure your precious pet fish have the best living conditions.
Not only that, but it also guarantees beneficial nutrients reach your aquarium plants’ roots.
If you are still undecided which among these options is the best, we suggest giving the Penn-Plax Clear-Free Under Gravel Filter a try.
It’s so easy to assemble that even novice fishkeepers will have no issues with installation. It even requires little upkeep.
If you have a smaller tank, choose the Lee’s 13210 instead. It’s small enough for 10-gallon tanks, but you can use several of the same tank filter if you decide to upsize.