Submersible fish tank filters are a great option for aquariums. They are quieter as their pump is submerged under the water. These filters don’t require additional space outside the aquarium and can be hidden inside it by blending them with the decorations. There are many submersible fish tank filters available in the market. They have varying specifications and may operate differently.
Types of Submersible Fish Tank Filters
Submersible fish tank filters can be broadly categorized into two types based on their functioning.
Pump-Powered Filters

Pump-powered submersible fish tank filters are quite commonly found in small aquariums. The device consists of a small canister with a pump along with sponges and filtration media (chemical and biological). The pump is generally located at the top or bottom of the filter. It sucks water through the sponges, trapping debris and waste for mechanical filtration, and then pushes it into the compartments with biological and chemical filtration media. Smaller and older models may only have a single compartment for filtration media. Pump-powered submersible fish tank filters have a valve that allows you to adjust the water’s flow rate. Many of them have integrated aeration devices for blowing bubbles into the water.
Air-Powered Filters

Air-powered submersible fish tank filters used to be popular but are rarely employed nowadays. They are beneficial when the water current in an aquarium must be kept to a minimum. Their gentle flow ensures that small fish are not sucked into the filter. Air-powered filters don’t have an integrated pump. Instead, they are used with an aquarium air pump. You connect the filter to a pump for cleaning the water. The flow rate of air-powered submersible fish tank filters will depend on the air pump’s pressure. They employ thinner foams or sponges for filtration. Compartments for additional filtration media are rarely present in them. As a result, air-powered filters have a poorer efficiency and don’t clean a tank as well as pump-powered filters.
When to Use Submersible Fish Tank Filters?
Submersible fish tank filters are generally suitable for small aquariums. They have a compact size as they must be installed internally. It limits the amount of media that can be added to them as compared to external filters. Therefore, they require frequent maintenance as the filtration media will get saturated quicker due to its limited quantity. However, the process of cleaning and maintaining submersible fish tank filters is relatively easy.
Also, the condition of the water in the tank will be acceptable but not up to the same levels as an external filter. Therefore, they are more suitable for aquariums with hardy fish species. They will do well in sparsely populated aquariums but may not be adequate when keeping a lot of fish in the tank.
Submersible fish tank filters are cheaper as compared to external filters. They don’t require additional installation space and can be placed in a corner or the rear side of the aquarium. If you are on a budget or short on space, such a filter may make sense.
Choosing a Submersible Fish Tank Filter
Submersible fish tank filters are available from different manufacturers and come in various capacities. There are a few considerations to keep in mind when choosing a model.
Capacity/Size of Fish Tank
The first thing to consider when choosing a submersible fish tank filter is the size of your aquarium. These devices have different flow rates, which is stated in gallons per hour (GPH). Their manufacturer specifies the tank capacity that the filter is suitable for, generally expressed in gallons. Select a submersible fish tank filter that provides an adequate flow rate for your tank’s capacity. Using a smaller filter for a larger tank will degrade the water quality and shorten the device’s lifespan.
Filtration Media
Submersible fish tank filters may have one or more types of filtration media in addition to a foam or sponge. Some of them only have a compartment for biological filtration media, while others also accommodate chemical media. A few premium filters also include activated charcoal to remove impurities and odor. Submersible fish tank filters with more filtration media clean water better, but they are also expensive to buy and maintain. Consider a model that provides adequate filtration for the fish you keep and the maintenance your tank requires.
Best Submersible Fish Tank Filters
If you are looking for the best submersible fish tank filters for aquariums, then here are a few great options for you.
If you are looking for the best submersible fish tank filters for aquariums, then here are a few great options for you.
1. NO.17 Submersible Aquarium Internal Filter
Aqua Pump NO.17 Aquarium Internal Filter is a highly-recommended option for the buyers searching for the best submersible fish tank filters. It has a maximum flow rate of 200GPH and will be suitable for 10 to 50-gallon aquariums. The pump has a maximum lift height of up to 3.28 feet, which is adequate for most fish tanks. It uses multiple filtration media to keep fresh and marine water aquariums clean and healthy. The 3-stage modular design allows you to use the No.17 internal filter as a 1-stage or 2-stage filtration device. You can also use the pump in standalone mode. It is super-quiet and consumes only 8-watts of power. A smaller 132GPH variant of the internal filter is also available.
2. Tetra Whisper In-Tank Filter with BioScrubber
Tetra Whisper is one of the best submersible fish tank filters available today. It makes use of Bio-Bag filter cartridges for cleaning the water and keeping aquatic life healthy. Its cartridge floss filters physical debris such as food particles and fish waste. The ultra-activated carbon filtration media deodorizes water and removes discoloration. It has a tank clip and suction cups that provide multiple installation options. Tetra Whisper in-tank filter is available in multiple variants that will be suitable for up to 3-gallon, 4-gallon, 10-gallon, 20-gallon, and 40-gallon fish tanks respectively. You can also use them in terrariums.
3. Aqueon Quietflow Internal Power Filter
Aqueon Quietflow internal power filter is a popular choice of the hobbyists who are looking for the best submersible fish tank filters. It uses a 3-stage filtration process for keeping aquariums clean. The filter comes with dense foam for mechanical filtration, activated carbon for chemical filtration, and BioGrid for biological filtration. You can adjust the direction and height of return easily. It is fully submersible and can be installed vertically or horizontally. Aqueon Quietflow internal power filters come in 10-gallon, 15-gallon, 30-gallon, and 40-gallon variants. You may choose one depending on the size of your fish tank.
4. Hygger Aquarium Internal Filter
Aquarium owners seeking the best submersible fish tank filters can also consider the Hygger Aquarium Internal Filter. It makes use of a coarse sponge filter for removing physical particles and debris as well as activated carbon for getting rid of impurities and odor from the water. It comes with two water spray rods for creating a natural water flow. There are three variants of the Hygger Aquarium Internal Filter available – a 2.5Watt model for 1 to 5.5-gallon tanks, a 7Watt model for 2 to 10-gallon tanks, and an 11Watt model for 6 to 20-gallon fish tanks. They are suitable for freshwater, seawater, and turtle tanks.
5. Penn Plax Cascade 600 Submersible Aquarium Filter
Penn Plax Cascade 600 aquarium filter is an excellent product among the best submersible fish tank filters. It has a flow rate of 175GPH and will be suitable for 20 to 50-gallon aquariums. The filter is equipped with physical, chemical, and biological filtration media that remove unwanted toxins and debris from the water while promoting the growth of beneficial bacteria. You can adjust the rate and direction of water flow as desired. Penn Plax Cascade aquarium internal filters are available in lower capacity models as well that will be suitable for smaller fish tanks.
6. Fluval U3 Underwater Filter
Fluval U3 underwater filter is a great option for the buyers who want the best submersible fish tank filters. It uses a 3-stage filtration process for getting rid of physical, chemical, and biological impurities from the water. The filter comes with foam pads, activated carbon, and BioMax filtration media for the same. It can be used in fish tanks having a capacity ranging from 24 to 40 gallons. Its 3-way flow control with adjustable output enables you to regulate water speed and volume. Fluval Underwater filters also come in smaller and larger sizes for different capacity fish tanks.
7. Danner Supreme EZ Clean Internal Aquarium Filter Dual-Cartridge
Danner Supreme EZ Clean internal aquarium filter is an innovative product among the best submersible fish tank filters. Its highlight is the quick and easy to change cartridge that makes maintenance a breeze. Additionally, it also allows you to change the water in the tank, and you don’t need separate equipment for the same. Supreme EZ Clean filter is capable of mechanical, biological and chemical filtration for keeping your aquarium clean and fishes healthy. It is suitable for up to 55-gallon tanks. A single-cartridge variant of the Supreme EZ Clean filter is also available that can clean up to 30-gallon aquariums.
8. Interpet Life Flow Internal Power Filter
If you are looking for the best submersible fish tank filters, then the Interpet Life Flow internal power filter is an excellent offering for you. It uses a 5-stage filtration process for keeping your aquarium clean and healthy. The filter is equipped with mechanical floss, activated carbon, and Biomedia for physical, chemical, and biological filtration. It oxygenates the water and also has spheres for removing phosphates to prevent algae growth. The disposable filter cartridges used in the filter are easy to install and remove. Interpet Life Flow internal power filter is suitable for 3 to 10-gallon fish tanks.
9. EECOO Internal Filter
When it comes to the best submersible fish tank filters, EECOO aquarium internal filter is a versatile item. It is suitable for tanks with fishes, reptiles, turtles, and amphibians. There are activated carbon cartridges and bio-balls in the filter for removing chemicals and biological impurities while preventing odors and water discoloration. The filter has a flow rate of 600L/H (liters per hour) and is suitable for up to 40-gallon tanks. You can hang it on the side of the aquarium or fix it using suction cups. EECOO filter can be used in tanks with low water levels (5cm/1.97inch) and can create a waterfall.
10. COODIA Internal Green Water Killer Filter Aquarium Tank U-V Light Submersible Disinfection Pump
COODIA Internal Submersible Filter is a suitable choice for the buyers who are looking for a secondary filter for their aquariums. It is specifically designed for controlling harmful microorganisms and algae floating in your fish tank. It uses a 5Watt UVC bulb for the same. The filter prevents the water in the tank from turning green. It can’t get rid of physical or chemical impurities, and you will need a separate primary filter. COODIA Internal Green Water Killer Filter can clean up to 150-gallon aquariums and is suitable for both freshwater and marine water setups.