I bought a CO monitor a couple years back after reading some horror stories about CO poisoning in tanks from liveaboards, and seeing many posts from DandyDon who has done a great job with education about the subject here. I've been testing my tanks ever since.
I thought I'd share that my testing of tanks from my recent Cozumel trip returned fantastic results. My op gets their tanks from the main fill station, and I know some ops still fill their own, so your results may vary. But my data shows the main fill station is doing a wonderful job with their filters. Every tank I tested had, at most, a 1ppm variance from ambient levels, which were 1-2ppm. I never saw a tank go higher than 3ppm for the whole trip. Great results and better than the last time I was there 2 years ago when I saw variances of up to 3ppm above ambient from the fill station and 5ppm above ambient with an op that had their own fill station. (those levels were still safe). On this trip the Cozumel tanks were even cleaner than the tanks I was testing in Hawai'i a few months ago.
I'll still test every tank, but I'm happy to see them doing a great job at the main fill station. It's always fun to get questions from other divers when they see what I'm doing, and I inevitably get a few divers each trip saying "Ummm... can you test mine too?" after they ask what I'm doing.
I thought I'd share that my testing of tanks from my recent Cozumel trip returned fantastic results. My op gets their tanks from the main fill station, and I know some ops still fill their own, so your results may vary. But my data shows the main fill station is doing a wonderful job with their filters. Every tank I tested had, at most, a 1ppm variance from ambient levels, which were 1-2ppm. I never saw a tank go higher than 3ppm for the whole trip. Great results and better than the last time I was there 2 years ago when I saw variances of up to 3ppm above ambient from the fill station and 5ppm above ambient with an op that had their own fill station. (those levels were still safe). On this trip the Cozumel tanks were even cleaner than the tanks I was testing in Hawai'i a few months ago.
I'll still test every tank, but I'm happy to see them doing a great job at the main fill station. It's always fun to get questions from other divers when they see what I'm doing, and I inevitably get a few divers each trip saying "Ummm... can you test mine too?" after they ask what I'm doing.
