AQUALINE 5/8" ID Self-Sinking TubingAQUALINE self sinking pond and lake air supply tubing is, non kinking air supply tubing that will stay on the bottom of your pond or lake when filled with air from your compressor. This eliminates the need for weights on the air supply pond tubing. Our heavy duty pond and lake aeration systems self weighted air supply pond tubing is made from a thick walled extruded PVC making it very pliable (even in cold weather), easy to install and environmentally