Works in both fresh and saltwater For minnow buckets, live wells, and coolers Works with 12V, 110V, and D-battery powered pumps This 3″ around Airstone from Marine Metal Products is specially designed to aerate water and keep bait alive. The Airstone can be used in both fresh and saltwater of minnow buckets, live wells, coolers, and more. Tough and durable construction is weighted so it stays properly positioned on the bottom of your tank or bucket.