The Fluval AquaClear AC20 is a hang-on-back aquarium power filter designed for aquariums up to 20 gallons. It provides mechanical, chemical, and biological filtration in a compact HOB design for small freshwater and saltwater aquarium setups. The AquaClear AC20 uses an open media basket that allows aquarists to customize filter media based on the needs of the aquarium. It can be used for betta tanks, shrimp tanks with an intake sponge, nano aquariums, planted aquariums, quarantine systems, and other appropriately sized aquariums. Key Features Hang-On-Back Design: Installs on the back rim of compatible aquariums For Aquariums up to 20 Gallons: Suitable for many small freshwater and saltwater setups Adjustable Flow: Flow can be adjusted for different aquarium needs and livestock types Customizable Media Basket: Open basket design allows media to be adjusted or replaced Multi-Stage Filtration: Supports mechanical, chemical, and biological filtration Lift-Out Media Basket: Helps make routine maintenance easier Product Information Brand: Fluval Model: AquaClear AC20 Product Type: Hang-on-back power filter Aquarium Size: Up to 20 gallons Flow Rate: Approximately 100 GPH Filtration Stages: Mechanical, chemical, and biological Included Media: Foam insert, activated carbon, and BioMax media Use: Freshwater and saltwater aquariums Best Uses Betta aquariums when flow is adjusted appropriately Shrimp tanks with a pre-filter sponge Nano community aquariums Small planted aquariums Quarantine and hospital tanks Grow-out systems Small fish-only saltwater aquariums Filtration Benefits The Fluval AquaClear AC20 supports three common types of aquarium filtration. The foam insert helps collect debris and provides surface area for beneficial bacteria. Activated carbon can help remove some dissolved organics and discoloration. BioMax media provides additional surface area for biological filtration. The open media basket gives aquarists flexibility to adjust media choices based on stocking level, water clarity needs, planted tank goals, or maintenance routine. Setup & Maintenance Tips Rinse filter media before first use using aquarium-safe water Prime the filter according to the manufacturer’s instructions before plugging it in Use a pre-filter sponge on the intake for shrimp, fry, or very small fish Adjust flow as needed for bettas, shrimp, or gentle-flow setups Do not replace all biological media at one time Clean the impeller and intake as part of routine maintenance Check flow regularly and service the filter when output slows Frequently Asked Questions What size aquarium is the Fluval AquaClear AC20 for?The Fluval AquaClear AC20 is rated for aquariums up to 20 gallons. What is the flow rate of the AquaClear AC20?The AC20 has a listed flow rate of approximately 100 gallons per hour. Can I customize the Fluval AquaClear AC20 filter media?Yes. The AC20 has an open media basket that allows aquarists to adjust or replace filter media based on the needs of the aquarium. Is the AquaClear AC20 good for shrimp tanks?It can be used on shrimp tanks when paired with a pre-filter sponge on the intake to help protect shrimp and shrimplets. Is the AquaClear AC20 good for betta tanks?Yes, it can be used for betta aquariums when the flow is adjusted appropriately and the setup is properly cycled, heated, and maintained. Can the AquaClear AC20 be used on saltwater aquariums?Yes. The AC20 can be used on freshwater, marine, and FOWLR aquariums when properly maintained. How often should the AquaClear AC20 be cleaned?Maintenance frequency depends on aquarium size, stocking level, feeding, and bioload. Many aquariums benefit from filter inspection or cleaning every 2–4 weeks, but heavily stocked tanks may need more frequent service. Does the AC20 include filter media?Yes. The Fluval AquaClear AC20 typically includes a foam insert, activated carbon, and BioMax media. Available at Tropical Treasures Wyo The Fluval AquaClear AC20 Power Filter is a hang-on-back aquarium filter for aquariums up to 20 gallons. Visit Tropical Treasures Wyo in Cheyenne, Wyoming, to shop Fluval filters, filter media, aquarium supplies, water conditioners, heaters, fish food, live plants, shrimp supplies, betta supplies, and aquarium care essentials.