Click to expand Tap to zoom Ecoplus Medium Round Air Stone by EcoPlus Save 31% Original price $3.17 Current price $2.20 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Add to cart These great quality Air Stones aerate and add oxygen to the water in your reservoir or grow system. Circulates nutrients into the water and helps to maintain an even water temperature. Use with 3/16 in ID air line.