Check the listing for details. EcoPlus Round Air Stone / Large (5 pack). Condition: New. Listed at 45.00 USD. Enhance the oxygenation and circulation of your hydroponic system with the EcoPlus Round Air Stone. This air diffuser/air stone is designed to suit up to 10 gallons reservoir volume and comes in a set of 5, so you can distribute it across your hydroponic system. The air stone is made of high-quality material and has one outlet, making it a reliable option for your hydroponic needs. The EcoPlus Round Air Stone is a suitable addition to your water aeration equipment and hydroponic systems, providing you with larger bubbles and more oxygenation for your plants. Use this air stone in your garden, yard, or outdoor living space to keep your plants healthy and thriving. 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