An undergravel filter will pamper your fish…

…with the best biological filtration.

It is a great solution if you want a non-demanding aquarium.

Are you looking for more?

Throw a low cost and low maintenance into account…

…and you’ve got yourself a winning system.

With that in mind, check out our top picks below.


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Why We Love it:

  • Fantastic value for money
  • Perfect for larger tanks

  • Nearly effortless setup and maintenance



The Penn Plax filter is a reliable workhorse that will keep the water in your tank clean and clear with minimum effort and maintenance. It includes four plates and 1-inch adjustable lift tubes while hiding from the view for maximum aesthetics. Safe to use in both freshwater and saltwater tanks, this premium UG filter is a must have for all aquariums between 5 and 55 gallons.

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Why We Love it:

  • Thick multi-plate construction

  • Ideal for fresh & saltwater

  • Perfect for beginners



Lee’s is a robust filtration system for larger aquariums that’s truly worth the higher price tag. Large plate ensures that one’s enough for the whole tank. Its zigzag design maximizes the filtering surface area, enhancing biological filtration in a discreet design. Ideal for beginners, it’s also a great choice for a quarantine or breeding tank, or as a power filter backup system.

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Why We Love it:

  • Wallet-friendly filter

  • Compatible with Penn Plax replacement filters

  • Perfect for small to mid size tanks



Meet the UG filter that’ll keep your aquarium aesthetically pleasing and your wallet happy. Inexpensive yet highly reliable, it’s perfect for small to medium sized aquariums. Two filter replacement cartridges bring further value for money. Moreover, Imagitarium is compatible with Filt-a-Carb and Ammonia-X replacement filters. Super-easy to install and fitting just right, it’s a great choice for beginners and small tanks.

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Why We Love it:

  • Truly discreet

  • Perfect for big tanks

  • Excellent price tag



This undergravel circulation bar by Aquarium Equip is perfect for big or custom-made aquariums. It’s a tad harder to install but definitely worth the effort. Once you’ve secured it to the bottom of the tank, you can even connect it to a canister’s filter intake if you want to. Indeed, this circulation bar can be used with a wide variety of filters in home aquariums of all kinds.

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Why We Love it:

  • For freshwater and saltwater

  • Ideal for small tanks

  • Noiseless design

The ISTA filter is a perfect choice for a small 5-gallon aquarium. Easy to install even by a beginner and working in both freshwater and saltwater tanks, it impresses with its silent design. It won’t disturb you nor your fish. We also like its filter plate that is easy to connect to a filter pump, air pump, or submersible filter head. Coming at a price that won’t break the bank, this is undoubtedly a great undergravel filter for the starters.

Tips for Choosing an Undergravel Filter

Let’s face it:

Canister and HOB filters are far superior than the gravel filtration systems.

So, why should you invest in one?

Well, these kinds of filters have many advantages.

They are an ideal choice for undemanding aquariums or smaller quarantine and breeding tanks.

These filters offer the necessary biological filtration…

… while keeping your aquarium aesthetically appealing.

They are also easy to set up and maintain, thus perfect for beginners.

Not enough yet?

Know that gravel filtration systems are also cheap.

With this in mind, here’s what you should check before buying.

  • Size: Think about the size of your tank and choose an appropriate undergravel filter. These models vary in size from small filters suitable for fish bowls and aquariums of up to 5 gallons to big units to use in 50-gallon tanks. In big tanks, however, it is recommended to enhance filtration with a separate chemical or mechanical filter, especially if the tank is overpopulated.
  • Working mechanism: These filtration systems are typically used with air pumps placed down the pipe to create water flow. Such a system is cheap, but it could be ineffective when used as a standalone filter in a larger aquarium. Some filters may use a water pump – or power head – instead of the air pump. This component is placed on the upper side of the pipe and creates a stronger water flow. Thus, it enhances filtration. There are also some UG filters that use reverse-flow filtration technology. Such a filter pushes water up through the gravel rather than pulling it down, which could be advantageous sometimes; however, these systems consume a lot of energy and have rather low filtration rates.
  • Filtration type: While all UG filters provide the necessary biological filtration your fish need, some models also feature either an activated carbon filtration cartridge or filter floss mechanism designed to provide additional chemical or mechanical filtration. These filters could be a better option for larger aquariums, but they will still be more efficient in aquariums with light fish load.
  • Installation ease: Some styles of these filters consist of plates that are easy to place on the bottom of the tank and covered with gravel. Others are circulation bars that could be harder to keep on the bottom of the tank. If you’re just starting, a conventional UG filter could be your best bet.
  • Suitability: Last but not least, you should also consider the type of water you’re using. Most undergravel filters are suitable to use in both freshwater and saltwater aquariums, but there are some exceptions. To stay on the safe side, check the specs of the filter you like and make sure you can use it safely in your fish tank.

Wrapping It All Up

Using the right water filter is essential.

Whether you have a smaller aquarium or look for a standalone filter for your breeding or quarantine tank, an undergravel filter could be ideal.

We hope you have already spotted the best undergravel filter for your needs.

So, what do you think?

Would you rather go for a traditional undergravel filter or a circulation bar?

Are you looking for a standalone or backup filtration system?

Have you found a favorite on this list?

Share your thoughts by leaving a comment.