Ensure the health of your pet fish's home with our Aqua Culture Aquarium Bubble Stone Twin Pack. Bubble stones are an excellent addition to any aquarium because they oxygenate the water by diffusing gradual oxygen into the environment so that your fish can breathe. To use, attach the bubble stone to the airline tubing, hold the stone in place with gravel, other stones, or lead weights, and soak in the water at least one hour before turning on the air. Be sure to check out other Aqua Culture products like aquarium accessories, aquarium kits, terrarium lights, gravel, and more for all your aquarium and terrium needs.Regulate airflow through the use of the gang valve. Keep your fish happy and healthy with our Aqua Culture Aquarium Bubble Stone Twin Pack. Aqua Culture Aquarium Bubble Stone, Twin Pack: * Helps oxygenate water in your tank * Soak at least 1 hour before turning on the air * Regulate airflow with the gang valve * (2) blue bubble stones * Pair with other Aqua Culture products