Best 20 Gallon Tank Aquarium Filters of 2025

The Aqueon QuietFlow 10 LED PRO Aquarium Fish Tank Power Filter is a great choice for up to 20 gallon aquariums. It features an LED indicator light that flashes when water cannot pass through the cartridge, a self-priming filter pump that will auto-start or restart if power is interrupted, and provides mechanical, chemical, and biological filtration. Customers love the new design of the filter, where the motor is inside the tank, and appreciate the high flow rates for optimal oxygen content. The filter is also easy to clean and maintain.

The TARARIUM U-V Filter is designed to keep your aquarium water crystal clear, often transforming cloudy or green water within just a few days. With its dual filtration system, it combines a biochemical sponge filter with a powerful U-V light, effectively improving water quality and reducing the need for frequent water changes. You can easily control both the pump and the U-V light separately, allowing for flexibility in operation. Plus, this filter helps eliminate unpleasant odors, ensuring a fresher environment for your aquatic friends. You can quickly check the U-V light's status without needing to disassemble the unit, adding to its convenience.

The AquaClear 20 Power Filter is an energy efficient aquarium filtration system that provides superior contact time with filter media, resulting in optimal mechanical, chemical, and biological filtration. Its quick and easy installation process makes it convenient for users to maintain, and it comes equipped with AquaClear Foam, Activated Carbon Filter, BioMax, and Cycle Guard to ensure superior water quality. With a filtration volume up to 7 times larger than comparable fish tank filters, this product is perfect for aquariums ranging from 5 to 20 gallons in size.

The Aqueon Power Filter features SmartClean technology, making water changes easy and quick. You can enhance your aquarium's water quality in just three simple steps, ensuring a cleaner environment for your fish. It comes with an EcoRenew Cartridge, which is eco-friendly, biodegradable, and compostable, contributing to a sustainable aquarium. The Bio-Holster securely holds the cartridge, promoting effective biological filtration while the NoDrip basin design reduces spills during cartridge changes, making maintenance hassle-free. This filter is perfect for both fresh and saltwater aquariums, providing versatility for different setups.

The DaToo 5W Filter is designed to create a clean and healthy environment for your fish. Its advanced three-layer filtration system effectively removes harmful impurities and odors, ensuring clear and stable water. You’ll appreciate the sturdy construction, made from durable materials that resist damage and enhance safety for your aquatic pets. Plus, the ultra-quiet operation allows you to enjoy peaceful nights without disruptive noise. With a DIY filter mode, you can customize the filtration process to meet your tank's specific needs, making it a versatile choice for any aquarium enthusiast.

MEWTOGO Aquarium Filter Replacement for EZ-Change #2, also known as the MEWTOGO Aquarium Filter, is a high-quality replacement cartridge designed for 10-20 gallon power filters. Each cartridge is packed with efficient activated carbon, which effectively removes impurities and odors from the aquarium water, ensuring a fresh and clean environment for your fish. The thickened filter spray cotton on the exterior of the cartridge filters out impurities, dust, and garbage, providing pure water for your aquatic pets. It is recommended to replace the cartridge every 2-4 weeks to maintain optimal filtering performance. The MEWTOGO Aquarium Filter is simple to use, just shake, rinse, and insert into the filter. Upgrade your aquarium filtration system with this reliable and convenient replacement cartridge.

The coospider-repta Hang On Filter is designed to keep your aquarium clean and healthy. With its four-layer filtration system, it effectively removes debris and harmful substances, ensuring optimal water quality for your fish. Enjoy a peaceful atmosphere with its whisper-quiet operation, making it perfect for home or office use. The specialized intake guard protects small fish and shrimp from being sucked in, providing a safer environment for all your aquatic pets. Plus, the adjustable flow rate allows you to customize water movement to suit delicate species or larger tanks.

The OQTTNEO Fish Tank Filter is designed to keep your aquarium clean and healthy. With its powerful motor and extensive bio filter sponge, it effectively eliminates impurities and harmful substances, ensuring your water remains crystal clear. The impressive 320 GPH pump promotes strong water circulation and oxygenation, which is essential for the well-being of your fish and plants. Moreover, installation is a breeze thanks to the included suction cups and straightforward instructions. The compact design not only saves space but also enhances the swimming area for your aquatic pets, combining beauty with functionality.

The NICREW Aquarium Internal Filter is a submersible power filter with multiple functions, designed to provide effective and thorough biological and chemical filtration for aquariums 10-20 gallons in size. It comes with adjustable air regulator, four suction cups for secure in-tank installation, and is suitable for both freshwater and saltwater tanks. It is also equipped with activated carbon and fine filter foam to trap debris and fish waste, absorb odors, and generate abundant air bubbles and water flow.

The FEDOUR Submersible Aquarium Internal Filter is a powerful filter that is suitable for 1-20 gallon fish tanks. It has excellent filtration performance, can absorb and get rid of grease and other dirt to clean water, and can provide oxygen for your fish tank. It is easy to install and comes with adjustable water flow. However, the flow adjuster may not work and the filter may stop working when the water line gets lower than the spray bar.