Tanks sometimes become an afterthought to many divers. "I'll just rent whatever they got!" they say, but they're missing the point. Having the right tank for you can make a huge difference in your buoyancy and overall comfort while diving. Between steel and aluminum, steel has the advantage of being negatively buoyant, meaning that once your tank is nearly empty it won't make you float. Aluminum tanks on the other hand are cheaper and lighter, and also come in a lot of cute colors. Tanks are also made in different dimensions, and for shorter divers having a shorter tank makes a world of difference in terms of mobility underwater.