7" Round Aluminum Oxide Airstones Union the material is produced to

the material is produced to high quality standards for consistency

Multiple Fountain Patterns for the Price of One

totally resists compression

less active bacterial layer

7" Round Aluminum Oxide Airstones Union the material is produced toDescription Unlike the standard silica airstones, these can be cleaned time and time again without wearing down. These airstones are made of aluminum oxide, the same material used for grinding stones which makes them extremely durable. With increased durability, there has been nothing sacrificed in the quality of aeration delivered to your pond, tank or lagoon. These stones have been specifically designed to work well in an earth bottom pond. The 7