This plastic air stone is biodiesel proof and is used for bubble washing biodiesel.

One air stone is adequate for washing a large tank of biodiesel, we use them on batches of 300 liters and they work perfectly.

They are easy to clean with a bit of isopropyl alcohol should they ever clog up.

They are fitted with a chromed steel fitting which allows the air line to be connected easily. Use a little silicone rubber on the pipe before pushing in the air line to ensure that it will not come out.