Shop All Scuba Tanks & Accessories

Key Takeaways

• Essential Life Support: Your scuba tank is the heart of your life support system, storing highly compressed breathing gas safely to keep you breathing underwater.
• Material Matters: The two primary cylinder materials, aluminum and steel, offer drastically different buoyancy characteristics, pressures, and capacities.
• Buoyancy Control: Choosing the right scuba diving tank can help you streamline your weighting system, drop unnecessary lead, and improve your underwater trim.
• Maintenance is Crucial: Annual visual inspections (VIP) and regular hydrostatic tests (every five years) are legally and practically necessary to keep your cylinder safe and functional.

The Role of a Scuba Tank

At its most basic level, a scuba tank (also known as a scuba cylinder) is designed to store and transport high-pressure breathing gas usually compressed air or enriched air nitrox so that you can breathe comfortably while submerged. Connected to your first-stage regulator, the cylinder reduces the immense pressure inside down to an ambient breathing pressure.

A reliable scuba tank does more than just hold air; it directly impacts your safety, dive duration, and physical comfort in the water. Because gas is compressed to hundreds of times normal atmospheric pressure (typically between 3,000 to 3,442 psi), the structural integrity of these cylinders must be impeccable. The right scuba tank provides a sufficient amount of gas for your target depth and dive time while seamlessly integrating with your BCD (Buoyancy Control Device) and overall diving rig.

Types of Scuba Tanks and Uses

When shopping for a scuba tank, you will quickly notice the options are broadly categorized by the metal they are forged from: aluminum and steel. Each type serves different purposes and excels in specific diving conditions. So, it pays to choose the right tank for the type of diving you do.

Aluminum Scuba Tanks

Aluminum cylinders are the industry standard for recreational dive centers, training facilities, and resorts globally. The most popular size is the Aluminum 80 (AL80), which holds approximately 77.4 cubic feet of air at 3,000 psi.

Aluminum is a softer, lighter metal than steel, meaning the walls of an aluminum tank must be thicker to handle high pressure. A unique characteristic of aluminum cylinders is their buoyancy shift. When full, an AL80 is slightly negatively buoyant, but as you breathe down the gas during your dive, the tank becomes positively buoyant. Divers must account for this by carrying additional lead weight to ensure they can easily hold a 15-foot safety stop at the end of their dive. Aluminum tanks are highly resistant to structural rust (though they can oxidize), making them excellent, low-maintenance choices for warm water and saltwater environments.

Steel Scuba Diving Tanks

Steel cylinders are heavily favored by cold water divers, technical divers, and those who want a higher gas capacity without adding excessive bulk to their back. Because steel is inherently stronger than aluminum, the walls of the cylinder can be thinner while safely holding higher pressures (often up to 3,442 psi for High-Pressure steel tanks). Steel tanks are also available in low pressure (LP) versions, typically rated to 2,640 psi, alongside the more common high pressure (HP) configurations.

A major advantage of a steel scuba diving tank is that it remains negatively buoyant throughout the entire dive, even when completely empty. This allows divers to take several pounds of lead off their weight belt or weight-integrated BCD, reducing strain on the lower back and vastly improving underwater trim. While steel tanks are generally more expensive upfront, their durability and longevity make them an excellent long-term investment. Keep in mind that steel is susceptible to internal rust if moisture enters the cylinder, so careful filling and maintenance are required.

Choosing the Right Tank for Your Needs

Selecting the perfect tank, and deciding between steel and aluminium requires evaluating your typical diving environment, physical size, air consumption rate, and budget. For those who travel frequently or prefer a budget-friendly, low-maintenance option, an aluminum AL80 or AL63 might be the ideal fit. Conversely, if you dive locally in a thick wetsuit or drysuit and want to optimize your gas supply, a high-pressure steel 100 (HP100) or HP120 will offer vastly superior performance.

Additionally, you must decide between valve types. The Yoke valve (also known as A-clamp or INT) is the most common in recreational diving in the Americas, while a DIN valve, which screws directly into the tank, provides a more secure, high-pressure seal preferred by technical and European divers. Thankfully, many modern Pro valves are easily convertible with an Allen key insert.

To take a much deeper dive into sizing, valves, and specific brand models, check out our highly detailed scuba tank buying guide. Furthermore, because switching from an aluminum tank to a steel tank drastically alters your buoyancy profile, you will need to adjust your lead accordingly. For expert tips on getting your buoyancy dialed in perfectly for your new tank, read our comprehensive guide on how much weight for scuba diving.

Browse the full selection today and take advantage of free shipping on thousands of products. Need help choosing? Call our customer service team, who will be happy to help.

Scuba Tanks For Sale: FAQs

How long does a scuba tank last underwater?

The duration a scuba tank lasts depends entirely on the diver's breathing rate, the tank's total volume, and the depth of the dive. Because water is dense, at 33 feet (10 meters), you consume air twice as fast as you do at the surface. A standard AL80 might last an average diver anywhere from 45 to 60 minutes on a shallow recreational dive, whereas a larger HP120 steel tank will significantly extend bottom time for that exact same diver.

How often does a scuba tank need to be inspected?

Safety regulations mandate two distinct types of inspections for all cylinders. First, a Visual Inspection (VIP) must be performed by a certified technician once every year. The technician inspects the threads, valve, and interior/exterior walls for cracks, corrosion, or pitting. Second, Hydrostatic testing (Hydro) is required every five years. During a Hydro, the tank is filled with water and pressurized beyond its normal working limit to measure expansion and ensure structural integrity.

Can I use Enriched Air Nitrox in any tank?

While the physical cylinder itself can hold Nitrox, it must be properly cleaned and prepared. If you plan to fill your scuba diving tank with gas mixtures containing more than 40% oxygen, or if your local dive shop uses a partial-pressure blending method to mix standard Nitrox, the cylinder and valve must be "Oxygen Cleaned." Always ensure your tank is outfitted with the proper green and yellow Nitrox decals to clearly identify its contents.

Do scuba tanks come with valves?

Most brand new scuba tanks for sale do come with a standard valve included (usually a convertible Pro Valve that can accommodate both Yoke and DIN regulators), but you should always check the specific product description to be certain. The valve is a critical component of the cylinder and must match the first stage setup of your regulator.

Do scua tanks come with gauges?

No, scuba cylinders do not come with gauges as standard. You can shop our range of scuba gauges or shop our full range of complete BCD packages which include packages with valves and/ or tanks.