Deluxe 4 Inch Round Air Stone for Hydroponic Systems, Fresh Water & Saltwater Aquariums, Aquaculture, Terrariums! The Deluxe 4 Inch Round Air Stone Disc 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 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 In aquariums the durable plastic can be buried or hidden to add to your dcor Uses a standard tubing connection, helps to maintain an even water temperature Package contains one Deluxe 4 Inch Air Stone Disc. Consider these other items: hydroponics air pump, aquarium air pump, airline tubing, check valves, Blue Spotted Betta Log, betta net, betta fish, betta tank and Blue Spotted betta leaf.