Aquarium Air Stone Balls, 2 Inch Fine Bubble Aerator for Aquariums, Hydroponics, Ponds and DWC Systems (Pack of 4)

Dense fine bubbles: produces a rich flow of small bubbles to increase dissolved oxygen, improve water circulation, and create a lively underwater environment. Versatile use: ideal for aquariums, DWC hydroponics, aquaponics, aeration of nutrient solutions, and prevention of pond surface freezing in winter. Durable construction - made from mineral materials, high temperature sintered for long lasting performance and safe use in all forms of aquatic life. Perfect size: each airstone measures 5 cm in diameter; fits a 4 mm or 3/8" tube; recommended pump power: > 4 W for optimal bubbling. Easy installation and maintenance: soak in water for 30-60 minutes before first use, and clean regularly to maintain strong bubble output.