🐠 Dive into clarity with the ultimate undergravel filter! Filters and aerates your aquarium simultaneously. Everything you need for setup right out of the box. Minimal moving parts for hassle-free upkeep. Perfect for 20-29 gallon freshwater and saltwater tanks. Experience the charm of classic filtration with modern efficiency. Crystal-clear filtration Easy maintenance Aeration system The Penn-Plax Undergravel Aquarium Filter is designed for 20 to 29-gallon tanks, featuring two 14” x 11.1” plates that provide biological, chemical, and physical filtration. This air-driven system not only keeps your aquarium water crystal clear but also aerates it, ensuring a healthy environment for your aquatic life. With easy maintenance and a complete kit included, it's the perfect solution for both freshwater and saltwater enthusiasts.