I am a little perplexed. I got a tank from Todds Scuba at Twin Quarries in Circleville, OH. It was brand new and never filled. I was going to put it in service for Nitrox but I needed it on Sunday while I was there so I had it filled twice. I dumped the air and looked inside the tank and saw black spots all over the inside. The date the tank was made as 06/09 and a visual of 7/09. Black spots, correct me if I am wrong; are from a compressor throwing oil into the air. Does this mean that I should no longer get fills there? CO posioning can kill and add Nitrox to oil and you may blow up the dive shop. Any opinions? Now the stupid tank would need cleaned. Or I could just make it only Air it would almost be cheaper to buy another tank already Oxygen certified. It also makes me wonder if I should have my first stage cleaned as well.