To keep your fish happy and healthy, a good aquarium filter is what you need. Finding a good aquarium filter is easier said than done. There are plenty of options to choose from, and not all of them are good.
Today, we are here to help you find the best 20 gallon aquarium filter that your money can buy. Let’s take a look at 5 great options for you to consider right now.
Our Top Picks
Best 20 Gallon Aquarium Filter: Reviews
AquaClear Fish Tank Filter
The AquaClear is designed for fish tanks anywhere from 10 to 30 gallons. It features an adjustable flow rate, so you can adjust it for your aquarium as needed.
On that note, the maximum flow rate is 150 gallons per hour. It can therefore filter a 20 gallon tank well over seven times per hour.
Keep in mind that this is a HOB or hang on back filter. This is beneficial as it helps to save space within the tank. On that note, this type of filter is also very easy to set up and to maintain. As long as you clean and replace the media, it doesn’t require much work other than that.
This unit comes complete with all three major types of filtration. Moreover, it also comes complete with all the media your need to get started. It comes complete with mechanical, chemical, and biological filtration media.
What you may also appreciate about this unit is that it is extremely energy efficient. It keeps energy costs to a minimum. Moreover, this aquarium filter can be used for both freshwater and saltwater tanks. This is an impressive feature that not all too many filters come with.
Pros
- Space efficient
- Great filtration capacity
- All three major types of filtration
- Easy to maintain
- Adjustable flow rate
- Filter media included
Cons
- Somewhat limited durability
- Makes a bit of noise
GRECH CBG-800 5W UV Sterilizer Hang-On Back Filter
Here we have another very space-efficient hang-on back filter for you to consider. Filters like this are always convenient because they don’t take up much space inside of the tank. They’re also convenient because they’re very easy to get into in order to maintain them.
This particular filter is designed to be used with tanks between 20 and 50 gallons. It features an adjustable flow rate that can reach up to 211 gallons per hour.
In terms of a 20 gallon tank, it can filter the same water over 10 times per hour. This is more than enough to keep any 20 gallon tank crystal clear and clean.
This filter comes complete with all three major types of filtration, with both biological and chemical media included.
What really stands out here is that this unit comes complete with a UV sterilizer. This helps to kill algae and various other unwanted organisms in the water. It also helps to remove surface oil from the water.
Pros
- Convenient hang on back design
- All three major types of filtration
- Added UV sterilization
- Easy maintenance
- Fairly durable design
Cons
- Not overly energy efficient
- UV bulb needs to be replaced regularly
Fluval C Series Power Filter
Here we have a fantastic aquarium filter that features five stages of water filtration. It features two stages of mechanical filtration, two stages of biological filtration, and chemical filtration. Thanks to this, it has great filtration capabilities that will help to keep aquariums clean and clear.
What is worth noting is that all of the filtration media comes included with your purchase. This media is very easy to change and maintain, which is thanks to the convenient design of this filter.
Hang on back power filters tend to be convenient in this sense. There is also the fact that they help to save space within the tank.
This particular unit is designed for aquariums between 20 and 50 gallons in size. It can easily filter the water in a 20 gallon tank over six times per hour.
Between the types of media and the flow rate here, you can rest assured that this filter will keep your aquarium clean. It is also worth noting that this particular filter is extremely quiet.
Pros
- 5 stages of filtration
- Filter media included
- Great flow rate
- Easy to set up
- Fast maintenance
- Quiet
Cons
- Lots of media that needs to be replaced regularly
- Components are not overly durable
Fluval U Series Underwater Filter
Here we have a great submersible filter for you to check out. Now, it is submersible, so it does take up space inside of the tank. However, some people do like how it looks. You cannot really see this filter from outside the tank unless you look for it.
What is convenient about this filter is that it has a special fliptop design. This means that it is very easy to get inside of it in order to perform maintenance on it.
This particular filter is definitely ideal for 20 gallon tanks. Its maximum flow rate is 155 gallons per hour. This means that it can filter a 20 gallon tank well over 7 times per hour.
This filter comes complete with all three stages of water filtration. It performs mechanical, biological, and chemical filtration. The media within this filter is also extremely easy to replace.
You might also like how this filter features a triple output. It releases water into the bottom, the middle, and the top of the tank. This is ideal as it helps a lot with water aeration and oxygenation.
Pros
- All 3 stages of filtration
- Easy maintenance
- Out of the way
- Great for aeration
- Durable design
- Great flow rate
Cons
- Takes up space inside the tank
MarineLand Magnum Polishing Internal Canister Filter
Here we have a very large filter that is designed for aquariums up just 97 gallons in size. This unit can process over 290 gallons of water per hour. For a 20 gallon tank, it could filter the entirety of the tank nearly 15 times per hour. This is definitely more than enough flow to keep your tank clean.
Keep in mind that this is an internal canister filter. This means that it does take up some space inside of the tank. However, if placed right, you can’t really see it, thus adding to the aesthetic appeal of your tank.
Remember that the main point of this filter is for water polishing. It does come with the Micron cartridge for water polishing included.
It also features two refillable chambers that can house either carbon or customizable filter media. However, it doesn’t come with any other filter included. It also cannot engage in all three major types of filtration at once.
Pros
- Designed for polishing
- Customizable media options
- Huge flow rate
- Easy to maintain
- Durable design
Cons
- May be too large for a 20 gallon tank
- Cannot perform all three major types of filtration at once
Conclusion
If you need something simple yet effective, it’s the AquaClear Fish Tank Filter we recommend. However, if you have a very large tank, then the MarineLand Magnum Polishing Internal Canister Filter is a good one to consider as well.
Ben Morales
Aquarist & Writer 15+ Years