How to choose a cylinder?
Your primary considerations in choosing a scuba tank are size, capacity and buoyancy.
You generally want the largest tank you can wear comfortably and carry. But, if you’re a smaller person, a smaller tank may provide ample air to make the same length dive as a larger person with a larger tank. Diving with enriched air nitrox is increasingly common and has a lot of advantages. Ask your PADI Dive Shop or Resort about your options for this in your area.Obviously, your regulator and tank should both be DIN or yoke system.