Hygger Blue Bubble Stone increases oxygen level in the water as well as adds beauty to your aquarium by producing a stream of tiny bubbles. Constructed from non-toxic mineral material covered with plentys of miniature holes, once connected with air pump, it will create a great mount of tiny bubbles. Suitable for aquarium, koi pond, hydroponic system, fish hatchery and aquaculture applications. Directions: Connect the air stone to the airline tubing and the airline tubing to the air pump. Place the air stone to the bottom of aquarium. Note: 1. Only presoak air stone for at least one hour, can the best effect of bubble be obtained. 2. Clean the surface of air stone regularly in case clogged.