HP Steel vs. LP Steel or Aluminum Tanks

For those looking to scuba dive in Key West, knowing which tank to use is the most important aspect of going on a dive. As such, here's everything you need to know about HP/LP steel and aluminum tanks.

Aluminum vs. Steel Tanks

There are a number of key differences between aluminum and steel tanks. For one, steel scuba tanks can be bought in low pressure and high pressure varieties, while aluminum tanks have varying pressures. Both tanks will slowly rust in ocean water, though this can typically be avoided with proper maintenance. In general, steel is a strong metal, while aluminum is much softer. This means that, in order for both tanks to hold the same amount of pressure, the metal on the aluminum tank needs to be thicker.

The buoyancy characteristics of the 2 types of tanks is also a distinct difference. As many divers know, the buoyancy of a tank can be very helpful when out on a scuba dive in Key West. Aluminum tanks are heavier, thus making them more susceptible to floating, meaning that the user must take on more weight at the beginning of the swim to compensate for this. A steel tank has what is called negative buoyancy, which only ever goes as high as neutral buoyancy, meaning that the user does not have to have as much weight with them during the dive.

The final significant difference between the two is that of the overall price. Steel tanks are far more expensive than aluminum ones, due primarily to their lighter weight and smaller form.

LP Steel vs. HP Steel Tanks

LP and HP stand for low pressure and high pressure. Pressures in scuba tanks can range anywhere from 2400 PSI to 3500 PSI. PSI stands for pounds per square inch, which refers to compressed air. Aluminum tanks can have a wide range of pressures, though typically fall anywhere from the standard 3000 PSI to 3300 PSI. The lower the pressure, the easier your equipment will be to handle. LP steel tanks often range from 2400 to 2700 PSI, while HP steel tanks can have a PSI of anywhere from 3300 to 3500. When buying a steel tank, it's also important to understand what overfilling is. Many tanks have the ability to add up to 10 percent more pressure than the allowed rate, meaning that a tank set to 3000 can actually fill up to 3300. However, if not done properly, this can be dangerous, so it's recommended that you always stay around or under the stated PSI.

Best Type of Tank to Use

If budget is not a concern, then a steel tank is likely the right choice to make. They are lighter and smaller than aluminum tanks and allow the user to carry less weight with them during their dive. Despite this, aluminum tanks are more commonly used and are still a great choice, particularly for those that may have a specific budget in mind.