Value Air Packs - Deluxe 4 Inch Round Air Stones With Airline & Air Control Kit Options for Aquariums, Terrariums, and Hydroponics! Value Air Packs - 2 Deluxe 4 Inch Round Air Stones with 25 feet of airline tubing & 11 piece air control kit for aquariums, terrariums, and hydroponics! The Deluxe 4 Inch Round Air Stone is a great way to oxygenate your hydroponic growing system or tropical fish aquarium. Provides a continuous ring of bubbles to help aerate your system. In aquariums the durable plastic can be buried or hidden to add to your dcor For hydroponics the micro-pore design energizes your growing solution as it aerates and circulates your nutrients. It will extend the life of your nutrient solutions. Helps to keep your roots healthy and promotes exceptional growth. The Deluxe 4 Inch Round Air Stone Disc is great to put at the bottom of your reservoir for aeration Uses a standard tubing connection, helps to maintain an even water temperature The professional silicone airline tubing is clear, flexible, and durable! Made for use in aquariums, terrariums, and hydroponics systems