Cylinder Fills Cylinders are filled on site at our premises in Clyde Street and can generally be filled with air (21% O2) while you wait. $11.00 per fill or buy a concession card of 10 fills for $85 (save $25, that's 2.5 fills for free!!!). Enriched Air fills for Enriched Air Nitrox certified divers takes longer and cost $16 per fill for up to 36% O2. Please note that any tank that is completely empty will have to be opened and inspected at the owners cost before filling for safety reasons. Pure Air: Our air is tested quarterly by NZUA, a third party EPA sanctioned test body in line with the regulations to ensure we comply and supply you with air safe for breathing underwater. We hope to be able to offer a quicker turnaround time for our Nitrox using customers in the furture. We just need to save our pennies for a second compressor that fills more slower than our "Big Boy Bauer" so that we can blend more accurately single tanks. We currently have to wait for about 6 cylinders needed the same blend to fill together.