Air stone disc-- aquarium air pump soak the product in water for 15 minutes before use. Round fish tank-- air stones are widely applicable for freshwater, saltwater aquariums, hydroponics or fish tanks. Aquarium air stones-- ?wide range of applicationthis air stone disc bubble diffuser is not only suitable for hydroponic systems, ponds, fish tanks, but also for freshwater or seawater aquariums, etc. the air stones are evenly out of air and the bubbles are fine, which can increase the content of oxygen in the water it is ideal for hydroponic systems to maintain the health of fish and plants and promote their growth. Betta accessories-- ??long use timesoaking the air in water for one hour before use. brush the surface every 2 weeks, you will find that he can accompany you for a long time and save a lot of money. Bubble stone-- made by high-quality material, it is safe, durable and useful.