The Air Stone -- Made of high quality and harmless mineral material Suitable for hydroponic systems, ponds, aquarium fish tanks, helping extend the life of your nutrient solution, keep fish/ roots healthy and promote plant growth. Aquarium air stones moderate in size and outputs a large steady stream of tiny bubbles, no leaks, add enough oxygen to your fish, and also make your fish tank more beautiful. Product Functions and Applications Great tool to add oxygen and circulate nutrition to your hydroponic growing system Produce fine bubbles for oxygen replacement, extend the life of your nutrient solution, keep roots healthy Disc design shell produce more bubbles Ideal for hydroponic systems, ponds, aquariums or fish tanks and other systems Note: Please soak the air stone in water for about 30 minutes before first use. The 6 inch air stone without sucker as the picture shown.