Best Scuba Tanks Review and Buying Guide

best scuba tanks review

The distinguishing piece of equipment for a scuba diver is their scuba tank. When it comes to diving, no other scuba gear is quite as critical to your survival, so you need the best scuba tank for the job. Despite knowing this, if this is your first time shopping for a scuba cylinder, you will likely be overwhelmed by all of the factors you need to consider before purchasing one.

In the past, you may be used to renting your tanks without really giving it much thought. But now that it’s time for you to own your own tank, the process is daunting and you don’t want to make a critical error. You are correct not to take this process lightly, and the aim of this article is to clear up any confusion and help you find a scuba tank that suits your diving needs.

A good scuba tank will safely sustain you underwater and endure any punishment thrown at it. Ideally, you will be using a steel tank, however aluminum tanks are a good budget option. If you take great care of your scuba tank, it can last for over a decade and pass multiple safety inspections. Let’s go over which scuba tanks are the most reliable so that you can dive with peace of mind.

Our Top Picks:

Sale Cyl-Tec New Stock 80CF Scuba Diving Tank - (3000 psi) Aluminum Diving Cylinder with Combo Valve

Best Steel Scuba Tanks

Faber FX Series 100 Cu. Ft. High Pressure Steel Tank

Faber FX Series 100 cu ft High Pressure Blue Steel Tank F-X Din/Yoke 3442 psi, Steel Scuba Tank,...
8 Reviews
Faber FX Series 100 cu ft High Pressure Blue Steel Tank F-X Din/Yoke 3442 psi, Steel Scuba Tank,...
  • The 100cf Faber Blue Steel FX Tank is an excellent high pressure steel tank.
  • F-x Series is a DOT E-13488 specification, no overfilling is allowed.
  • All F-X Series cylinders are oxygen cleaned and suitable for Nitrox use

Features:

  • Capacity: 100 cf
  • Measurements: 25.39” (64.50 cm) x 7.24” (18.42 cm)
  • Weight: 31.4 lbs (14.2 kg)
  • Buoyancy: Empty: -0.59 lbs (-0.15 kg); Full: -8.41 lbs (-3.81 kg)
  • Max Fill Pressure: 3442 PSI / 230 Bar
  • Materials: Chromium molybdenum steel

If you’re in the market for a galvanized steel scuba tank, then Faber is the only manufacturer of them, and a darn-good one at that. Faber tanks are the go-to for many scuba divers who prefer steel tanks over aluminum.

Why should you get a steel cylinder? After all, aluminum seems to be more popular and cheaper, however steel is more buoyant in the water and much more durable. Steel as a material is stronger than aluminum, so you actually need less of it for a durable tank, which means there’s more room for adding in air.

As for this particular model, the Faber FX series 100 cf, it is a great choice for someone looking to dive below 40ft. The 100 cf provides an air capacity that is 25% greater than an 80 cf tank.

Since steel tanks provide so many benefits, unfortunately they are on the more expensive side. However, they are worth the money because they can last for up to 15 years. Steel is a highly durable material that can take the beating of daily diving, and this model specifically is made from chromium molybdenum steel which is resilient.

Next, this is a high-pressure tank with a maximum fill pressure of 3442 psi (230 bar). It is Nitrox compatible up to 40%, with a 3/4″ – 14 NPSM thread. This tank has already been rigorously tested and comes with a valid VIP sticker and Hydro stamp. The only real downside of this Faber tank is that it’s quite expensive. Beginners may not find the investment worth it, particularly if they don’t dive frequently.

Furthermore, all of Faber’s tanks are triple protected with a combination of epoxy pain, a zinc galvanizing spray, and lastly, a polyurethane top coat. If you’re looking for the most durable and reliable galvanized steel scuba tank for longer dives, then the Faber FX Series 100 cf is the best scuba tank for the job.

Pros:

  • Lighter on land and more durable than aluminum.
  • Triple protected finish.
  • Reduced risk of sustained load cracking compared to aluminum tanks.

Cons:

  • Very expensive, not a good choice for beginners.

Faber Blue Steel HP 80 CF Scuba Tank

Features:

  • Capacity: 80 cf
  • Measurements: 20.87” (53.01 cm) x 7.24” (18.42 cm)
  • Weight: 28.60 lbs (13 kg)
  • Buoyancy: Empty: -1.74 lbs (-0.79 kg); Full: -8.05 lbs ( -3.65 kg)
  • Max Fill Pressure: 3442 PSI / 230 Bar
  • Materials: Chromium molybdenum steel

We’ve already established that Faber is the best steel scuba tank manufacturer, so it’s no surprise that we are pretty much exclusively recommending their tanks. This next tank is basically identical to the Faber FX 100 cf, except this is the 80 cf version. Which model you get depends on your diving experience and what kinds of dives you plan on doing.

Just like the FX 100 cf, this tank is similarly durable, with superior buoyancy compared to aluminum and a lower risk of sustained load cracking. Since it has a triple protected finish, it is corrosion-resistant, at least on the outside. Take care to not let it rust or corrode internally.

Furthermore, the Faber FX Blue Steel 80 cf has a convertible Pro Valve (DIN or yoke). It has a maximum fill capacity of 3442 psi (230 bar), and is lightweight at only 28.6 lbs (13 kg). For beginners who want a steel tank for shallow scuba diving, then this is the perfect option for you.

Pros:

  • Lighter on land than aluminum, and is negatively buoyant underwater even when empty.
  • This model is very light at 28.6 lbs, and is best-suited for shallow water divers.
  • Triple protected finish.
  • Lower risk of sustained load cracking.

Cons:

  • Steel tanks are more susceptible to corrosion compared to aluminum tanks. They require much more thorough cleaning after each session, particularly if diving in sea water. Regular maintenance is necessary to ensure no rusting or corrosion occurs.

Faber FX Series 120 cf HP Blue Steel Tank

Faber FX Series 120 cu ft High Pressure Blue Steel Tank F-X Din/Yoke 3442 psi
2 Reviews
Faber FX Series 120 cu ft High Pressure Blue Steel Tank F-X Din/Yoke 3442 psi
  • The 120cf Faber Blue Steel FX Tank is an excellent high pressure steel tank.
  • F-x Series is a DOT E-13488 specification, no overfilling is allowed.
  • All F-X Series cylinders are oxygen cleaned and suitable for Nitrox use.

Features:

  • Capacity: 120 cf
  • Measurements: 29.3” ( 74.42 cm) x 7.24” (18.39 cm)
  • Weight: 39.2 lbs (17.78 kg)
  • Buoyancy: Empty: 0.65 lbs (0.29 kg); Full: – 8.82 lbs (-4.0 kg)
  • Max Fill Pressure: 3442 psi (230 Bar)
  • Materials: Chromium molybdenum steel

Once again, we are recommending a Faber steel tank. Not only is Faber the only manufacturer of steel tanks in the US, despite having little competition, they continue to provide the most reliable and durable steel cylinders on the market.

As we mentioned, their tanks are the only ones that are galvanized. On top of that, an epoxy paint and a polyurethane coating is applied to ensure long-lasting durability and protection from the corrosive nature of seawater on steel.

This tank, the Faber FX 120 cf High Pressure has a capacity of 3442 psi (230 bar) and its large size means it is best suited for technical diving. Its 120 cf air capacity provides 50% more oxygen than an 80 cf tank, and 25% more than a 100 cf tank. This tank includes a convertible valve (DIN or yoke) and a self-draining boot.

Pros:

  • Impressive capacity.
  • Triple protected finish.
  • Self-draining boot.
  • Convertible valve (DIN or yoke).

Cons:

  • Extremely expensive; ideal for experienced divers.

Best Aluminum Scuba Tanks

Cyl-Tec 80CF Scuba Diving Tank

Sale
Cyl-Tec New Stock 80CF Scuba Diving Tank - (3000 psi) Aluminum Diving Cylinder with Combo Valve
152 Reviews
Cyl-Tec New Stock 80CF Scuba Diving Tank - (3000 psi) Aluminum Diving Cylinder with Combo Valve
  • This tank ships ready to fill (empty) and is DOT/TC certified. Federal law requires the tank be shipped unfilled.
  • Cyl-Tec's 3000 psi Scuba Diving Tank has an Air Capacity of 80 CF. Working Pressure = 3000 psi (207 bar)
  • Salt Water Buoyancy (Full) = -1.9 lbs; Salt Water Buoyancy (Empty) = 3.8 lbs

Features:

  • Capacity: 80 cf
  • Measurements:: 26.1″ (66.3 cm) x 7.25″ (18.42 cm)
  • Height with Valve: 29.75” (75.56 cm)
  • Weight: 31.4 lbs (14.2 kg)
  • Buoyancy: Empty: 3.8 lbs (1.72 kg); Full: -1.9 lbs/ (-0.86 kg)
  • Max Fill Pressure: 3000 PSI / 207 Bar
  • Materials: 6061-T6 Aluminum Brushed Finish Cylinder

Cyl-Tec scuba cylinders are Chinese-manufactured cylinders exported to the US. However, since all scuba tanks must adhere to the strict regulations outlined by the US Department of Transportation, you rest easy knowing that all tanks are very high in quality. And scuba diving is only one application in which this brand’s aluminum cylinders can be used for.

The Cyl-Tec 80 cf aluminum tank is one of the most lightweight tanks on the market. It is only slightly negatively buoyant want full, and very buoyant when empty, with a maximum fill pressure of 3000 psi (207 bar). It is constructed from high-strength 6061-T6 aluminum alloy and has a brushed finish. This keeps the tank from being magnetic and makes it corrosion resistant. This tank is also Nitrox ready which means it can accommodate mixes up to 40% oxygen.

Furthermore, the Cyl-Tec 80 cf tank is also one of the most affordable scuba cylinders on the market. Its low price is not indicative of cutting corners; as we mentioned, this tank had to pass the DOT’s standards to even be listed for sale. In fact, it even passed Transport Canada’s requirements and a whole slew of other safety departments as well.

On top of that, the Cyl-Tec have been established to provide high-quality, lightweight cylinders with a seamless construction. Overall, the Cyl-Tec 80 cf aluminum tank is perhaps the best scuba cylinder tank for a beginner diver who just wants a tank that is affordable and suitable for shallow water diving.

Pros:

  • Aluminum tanks are significantly more corrosion and rust-resistant than steel tanks. They oxidize, further guarding itself from corrosion. This tank is highly unlikely to rust due to the aluminum alloy used.
  • Comes with a Combo Valve that makes it usable with both yoke and DIN connections. To make a change, simply remove the center plug with an Allen wrench.

Cons:

  • Not ideal for deep diving due to its small capacity.
  • Aluminum tanks are heavier than steel tanks on land, but are more buoyant underwater.

Sea Pearls 80 cf Aluminum Tank

Sea Pearls 80 Aluminum Scuba Diving Air Tank 3000 PSI (Yellow, Delux K Valve VA100-30A)
35 Reviews

Features:

  • Capacity: 80 cf
  • Measurements: 29.75″ (75.56 cm) x 7.8” (19.81 cm)
  • Weight: 30.0 lbs (13.61 kg)
  • Buoyancy: Empty: 3.3 lbs ( 1.50 kg); Full: -1.5 lbs (-0.68 kg)
  • Max Fill Pressure: 3000 PSI / 207 Bar
  • Materials: High strength aluminum alloy

The Sea Pearls 80 cf aluminum tank is on the higher end of the price spectrum, but it’s well worth the money. Sea Pearls used to solely manufacture dive weights and are still a pioneer of high-quality dive weights, but they are trying their hand at manufacturing scuba tanks. They manufacture both aluminum and steel cylinders now, plus applicable accessories.

Using the same high standards they used for their dive weights, Sea Pearls applied it to their scuba cylinders. Sea Pearls have taken all the necessary steps to ensure this tank is as durable and reliable as possible. It comes with an up-to-date Hydro Stamp and VIP sticker, and is made from high-strength aluminum alloy.

Next, this tank has a maximum fill pressure of 3,000 psi (207 bar) and at a weight of only 30 lbs (13.61 kg), this is a very lightweight aluminum tank. The Sea Pearls 80 cf comes equipped with a 3/4 – 14 NPSM thread, which is ideal for a tank of this pressure. For convenience, this tank includes a high-compression stainless steel K-valve that is chrome plated. Not only is it more efficient, but it’s easier to use.

Pros:

  • Highly versatile; can be used to fill an air gun or spear gun if you desire.
  • Lightweight cylinder is easy to carry both in and out of the water.
  • Becomes positively buoyant as it empties.

Cons:

  • Only comes with a K-valve (yoke).

Catalina 80 cf Aluminum Tank

Features:

  • Capacity: 80 cf
  • Measurements: 25.9″ (65.80 cm) x 7.25” (18.42 cm)
  • Weight: 31.3 lbs (14.20 kg)
  • Buoyancy: Empty: 4.1 lbs ( 1.86kg); Full: -1.6 lbs ( -0.73 kg);
  • Max Fill Pressure: 3000 PSI / 207 Bar
  • Materials: High strength aluminum alloy 6061-T6

Catalina has been one of the largest suppliers of aluminum scuba tanks for over 30 years, and to date they now export to over 100 countries worldwide. In fact, if you’ve ever rented a scuba tank before, chances are you already came into contact with this tank, or at least a comparable Catalina model. Why are these tanks so widespread?

To start, their aluminum tanks are made from high-strength 6061-T6 aluminum alloy. This material is corrosion and rust-resistant, with long-lasting durability. The Catalina 80 cf is Nitrox ready up to 40% and has a maximum fill pressure of 3,000 psi (207 bar). It only weighs around 31 lbs so it is easy to handle.

Furthermore, this tank includes a Chrome-plated marine base and even comes with a Pro Valve for converting the air capacity for use with yoke or DIN components. And despite being an aluminum tank, this model is very hardy though not as resilient as a steel tank. For these features, you will have to pay a pretty penny. However, for the quality that you are getting, it is well worth it.

Pros:

  • Comes with a Pro Valve (DIN and yoke).
  • Nitrox up to 40% oxygen.
  • Comes with a high flow capacity valve.

Cons:

  • The chrome-plated marine base only works for sea water if manufactured correctly. The effectiveness of the chrome plating depends on the number of layers used and its overall thickness.

Sherwood Aluminum 100 cf Scuba Diving Tank

Sherwood Aluminum 100 CF Scuba Diving 3300 psi Dive Tank (Black)
5 Reviews
Sherwood Aluminum 100 CF Scuba Diving 3300 psi Dive Tank (Black)
  • Sherwood Aluminum 100 CF Scuba Diving 3300 psi Dive Tank
  • Pressure (psi): 3300 psi
  • Weight: 46.2 lbs

Features:

  • Capacity: 100 cf
  • Measurements: 30.3” (76.96 cm) x 8” (20.32 cm)
  • Weight: 46.2 lbs (21 kg)
  • Buoyancy: Full: -7.8 lbs (-3.54 kg)
  • Max Fill Pressure: 3300 PSI / 220 Bar
  • Materials: High strength aluminum alloy

Sherwood has been manufacturing dive tanks for over 60 years and to this day they are still one of the go-to brands. They have earned a reputation for delivering cylinders that are safe and reliable.

The Sherwood aluminum 100 cf is constructed using a high-strength aluminum alloy and it has a maximum fill pressure of 3,300 psi (220 bar). Weighing 46.2 lbs (21 kg), it is on the heavier side compared to other tanks. However, this just means it is more buoyant in the water. With 100 cf of space, that means you get 25% more air than an 80 cf tank.

Pros:

  • 100 cf and 3300 psi.
  • Highly corrosion-resistant.
  • More buoyant than most other tanks.

Cons:

  • With a weight of 46.2 lbs (20 kg), this is a very heavy tank.

Best Pony Bottles

You never know what might go wrong during a dive, so you should always prepare for the worst. It is never a bad idea to prepare a back-up device for any major piece of scuba equipment, and having a pony bottle as an emergency oxygen tank is critical. This is especially true if you go on deep dives as opposed to recreational diving.

In case an accident happens to you or something else, such as an unexpected tank failure, a redundant air source could be life-saving in such a catastrophic event. Pony bottles are miniature scuba tanks that only provide enough air to make a safe ascent back to the surface. They are not intended to replace a full-sized scuba tank.

Catalina Pony Bottle Tanks (5 Sizes)

Features:

  • Capacity: 6 cf; 13 cf; 16 cf; 30 cf and 40 cf
  • Max Fill Pressure: 3000 PSI / 207 Bar
  • Materials: High strength aluminum alloy 6061-T6

Catalina is one of the top suppliers of aluminum scuba tanks, and that quickly becomes apparent once you have a chance to use their products. The Catalina Pony Bottle is made to the same standard as their regular tanks, albeit it is much smaller. It comes in 5 different sizes, ranging from 6 cf to 40 cf, all with a maximum fill pressure of 3,000 psi (207 bar).

Since these tanks are so small, they add minimal extra weight to your scuba setup. In our opinion, the extra weight added is a negligible price to pay for the benefit of peace of mind and the extra oxygen it provides in the event of an emergency.

 

Pros:

  • Includes a Pro Valve which is a convertible K-Valve (DIN or yoke).
  • The valve provides excellent flow and is easy to operate. It also includes a multi-ported burst disc plug.
  • Five different sizes to choose from depending on your needs and skill level.

Cons:

  • This tank uses a chrome-plated marine base. Chrome plating’s usefulness is debatable; it must have enough layers and a proper thickness in order to be beneficial.

XS Scuba Aluminum Pony Bottle (4 Sizes)

Features:

  • Capacity: 6 cf; 13 cf; 19 cf and 30 cf
  • Max Fill Pressure: 3000 PSI / 207 Bar
  • Materials: High strength aluminum alloy

XS Scuba has been in the industry since 2002 and are a well-known supplier of scuba equipment – from wetsuits, knives, bags, valves, all the way to scuba tanks. They are a trusted one-stop shop for all things scuba, and their tanks are excellent as well.

The XS Scuba Aluminum Pony Bottle is available in 4 sizes ranging from 6cf to 30cf, and they are all constructed from high-strength aluminum alloy. Their maximum fill pressure is 3,000 psi (207 bar) and they include a convertible Pro valve (DIN or yoke).

These tanks have thick and resilient walls that can take a beating. Both the interior and exterior are rust and corrosion-resistant thanks to aluminum’s natural properties. Overall, this bottle is lightweight and should fit comfortably in most divers’ kits. It is easy to attach and will serve will as a reserve tank.

Pros:

  • Durable walls that are damage-resistant and corrosion-resistant.
  • Pro Valve (DIN or yoke).
  • Four sizes to choose from.

Cons:

  • Too buoyant when empty.

Luxfer Aluminum Pony Tank

Features:

  • Capacity: 6 cf; 19 cf and 30 cf
  • Max Fill Pressure: 3000 PSI / 207 Bar
  • Materials: High strength aluminum alloy L6X 6061-T6

Luxfer is a brand that is very popular with the US military, and it is used by both commercial and technical divers alike. They use a proprietary version of the standard 6061 aluminum alloy, called the L6X. This version completely surpasses the original in dependability and safety.

Their pony tank includes a Pro Valve (DIN or yoke) and is 23.5% Nitrox ready. It has a maximum fill pressure of 3,000 psi (207 bar). The Luxfer Pony Bottle comes in three sizes, from 6 cf to 30 cf. The smaller two tanks are ideal for use while recreationally diving, and the larger tank is perfect as a redundant air source for deep or technical diving. Be sure to select the appropriate size for your needs.

Pros:

  • Constructed using a proprietary version of aluminum alloy, the L6X 6061-T6 which is far more durable and reliable than the original.
  • Includes a Pro Valve (DIN or yoke).

Cons:

  • 30 cf is the largest available size.

Best Carbon Fiber Tank – IORMAN Universal 4500 psi

Features:

  • Capacity: 88 cf
  • Measurements: 22.1 (56.13 cm) x 6.9” (17.53 cm)
  • Weight: 70% less than traditional steel cylinders.
  • Max Fill Pressure: 4500 PSI / 310 Bar
  • Materials: Carbon fiber composite

This tank is unique because of its construction and the materials used. The Iorman carbon fiber tank has a carbon fiber exterior, and the interior liner is made from aluminum. The carbon fiber is then wrapped up in a protective fiberglass layer. It’s just layers and layers of protective material on top of each other, making it one of the most durable tanks available.

Furthermore, these materials are also lightweight, and one of the main features of the Iorman tank is that it’s unbelievably lightweight compared to steel and aluminum tanks. It only weighs about 4 kg (8.8 lbs), with a maximum fill pressure of 4,500 psi (310 bar) which is simply unheard of in commercial products. The tank is also fitted with a high-pressure gas cylinder valve.

According to the manufacturer, this scuba cylinder can last up to 15 years, which is about equivalent to what a well-maintained steel tank can last for. And since it is made from carbon fiber, there is no risk of the tank corroding. In other words, maintenance should be even easier compared to steel tanks.

Additionally, despite how lightweight the tank is, it is freakishly durable. In fact, not only is this cylinder designed to withstand impacts, but also to resist distorting under immense pressure.

This tank meets the DOT-SP-14621 standards.

Types of Scuba Tanks

It is difficult to classify scuba tanks into a specific type or category. Each one can differ in size, material, and the type of valve, so grouping them is not always so clear cut. In this section, we will go over some of the factors to consider when shopping for a scuba tank, starting with the most common materials they are constructed from.

Steel

Most dive professionals will agree that steel is the superior material in cylinder construction. This is because steel tanks are lighter on land and more durable overall. Steel tanks are lighter than aluminum tanks because steel is the stronger material. Therefore, less steel is needed to create the equivalent aluminum tank in terms of durability and fill pressure. In a similar vein, steel tanks have some of the highest capacities because manufacturers can simply make their tanks larger.

Thus, divers who see themselves spending a lot of time in the water in the future should invest in a durable and long-lasting steel tank. With the proper care and maintenance, steel tanks can last as long as 15 years. In other words, it can pass multiple safety inspections before it needs to be replaced.

As effective as steel tanks are, they do come with a few downsides as well. The first and most obvious one is its cost. Steel tanks are more expensive than aluminum tanks. If you are just starting out with diving or aren’t sure if you’ll be diving a lot in the future, a steel tank simply isn’t worth the investment.

The second issue is internal corrosion. Steel is susceptible to rusting, particularly the internal sections of the tank. This can compromise the integrity of the tank and is extremely dangerous if it happens, so proper maintenance of a steel tank is absolutely crucial.

Third, while steel is lighter on land, it’s a different story underwater. Steel becomes negatively buoyant, meaning it sinks in water. This is not necessarily a bad thing depending on your setup because less effort is required to stay underwater. However, as the air inside the tank depletes, steel tanks become less negatively buoyant but will never quite reach the point of positive buoyancy. Therefore, you will sink less than you used to, but you’ll still be sinking.

Aluminum

Moving onto another popular material used in cylinder construction. Aluminium tanks come with many benefits, however there is one major flaw to aluminum tanks that we must address which is that it’s not very durable. Unlike the resilient steel tank, any major impacts on an aluminum tank can compromise it. Since aluminum is brittle, manufacturers have to add multiple layers of aluminum to strengthen it. This makes aluminum tanks heavier and have less air capacity than steel tanks.

Why then would someone want to have an aluminum tank? To prevent the major flaw found in steel stanks. Aluminum tanks are corrosion-resistant far better than steel tanks. In fact, rather than rusting, this metal will oxidize, forming a protective layer which further resists corrosion. For this reason, aluminum tanks are arguably safer than steel tanks as long as they are properly maintained. Since you will be spending so much time in salt water, corrosion-resistance is a must.

Another benefit of aluminum tanks is their comparatively lower price. If you are just getting started or don’t plan on diving frequently, you might want to start off with an aluminum tank before investing in a more expensive one.

Lastly, keep in mind that aluminum tanks start off negatively buoyant but they become positively buoyant when empty. Depending on how you set up your dive weights, you may find yourself slowly rising to the surface as the tank depletes which can be annoying.

Carbon Fiber

Even though steel and aluminum are the two most popular tank options on the market, we have to give a special mention to carbon fiber.

There are three main benefits to using a carbon fiber tank. The first is that carbon fiber is a very light material which makes it comfortable to scuba with. Second is that, like aluminum, it is corrosion and rust resistant, so less maintenance is required. Lastly, carbon fiber can hold a significantly larger PSI, up to 5,000 PSI.

With all of these advantages, why then is carbon fiber not the de facto standard? The main reason is that they are a new development that has not yet been approved by the proper authorities such as the American Department of Transport. The second major issue is that they are currently prohibitively expensive, though some are more affordable than others.

Scuba Tank Buying Guide

Price

We can say all we want about how good a specific scuba tank is, however it’s all a moot point if its price is prohibitively expensive. Unfortunately, the biggest factor when purchasing a scuba tank is its price. We’ve mentioned already that steel tanks are more expensive than aluminum. If you don’t plan on diving very often, then financially, aluminum tanks are the better option.

Size and Air Capacity

There is a distinction between the size of a scuba tank and its air capacity. When thinking about the size of a tank, consider how it is going to fit on your body and with your scuba gear. Scuba tanks don’t come in small, medium, or large sizes the way clothing does. The tank size is expressed in volume, or its capacity to hold compressed gas. The standard units used are cubic feet (cf, imperial) and liters (L, metric).

Typically, the higher the volume, the more compressed gas it can contain. Most scuba tanks you will see in dive shops are 80cf or 10.2L at 3,000 psi (200 bar). If you have your own scuba tank, you can get one with a much higher volume such as 120cf or 15.3L. You can also bring a backup mini air supply with a lower air volume in case your main tank fails.

Most recreational divers use an 11L cylinder that holds 80cf of gas at a pressure of 3,000 PSI which should be sufficient for a bottom time that does not yet run the risk of decompression sickness. Younger or smaller divers may use a smaller scuba cylinder, such as a 9L AL 63 tank.

Furthermore,the most common sizes for aluminum cylinders are AL63, AL80, and AL100. Steel cylinders have more size options than aluminum, and some popular ones are HP50, HP80, HP117, HP133, and HP150.

As for air capacity, if you prefer to go on longer dives, then of course a larger air capacity is important. With that said, a tank that’s too large for you is going to be difficult to use underwater. Therefore, you have to consider both the size of a tank and how it lines up with your torso, in addition to its air capacity, before purchasing one.

The table below will give you approximate size measurements for some of the most popular tanks.

Height    Tank
20-21 Inches AL63, HP80
24 Inches HP100, HP117
26 Inches AL80, AL100
28-30 Inches HP120, HP133

While the tank height is an important consideration, the tank diameter is arguably the more important number. Most primary tanks, be it steel or aluminum, have a diameter of 7-¼ inches. Some of the larger capacity tanks, such as the AL100, HP117, and HP133 have a diameter of 8 inches, though the HP120 is also a 7-¼ inch tank. This should not be an issue for your BCD, but it may get annoying switching between two tank diameters by adjusting the tank bands. The issue is that some storage racks on dive boats don’t accommodate 8-inch diameter tanks.

Number of Tanks

Depending on the kind of dives you embark on, you may need to use more than one cylinder. If you plan on spending a long time underwater or performing multiple dives in one session, then you need additional scuba tanks. You may need more scuba tanks if the air capacity and size of the tank is insufficient for the dive you are planning.

Valves

All scuba tanks are sealed with a tank valve: either a Yoke valve or a DIN valve. In the past, yoke valves were primarily used in the United States, while DIN valves were the standard for European countries.

Nowadays, the availability of valve adapters and 1st stage regulator adapters has made it easy to switch between these two types. Keep in mind that yoke tanks can be adapted to work with DIN regs, but not necessarily the other way around. Both valve types rely on an O-ring to provide a tight seal from the tank valve to the first stage regulator.

PSI/Bar Pressure

Every scuba tank is technically a high-pressure vessel, however there are some designed for recreation with “standard”, “low”, and “mid” pressure as well. The units used to express pressure are PSI (pounds per square inch) and Bar. Both units are commonly used and you can convert between them if you know the value of one.

Though there are scuba tanks with a variety of pressure ratings, some popular options are low-pressure tanks (up to 2640 PSI, 180 bar), standard pressure tanks (3000 PSI, 200 bar), and high pressure tanks (3300 to 3500 PSI, 230 to 240 bar).

Since the amount of air pressure in a cylinder varies depending on if you have a low, mid, or high pressure one, there are a few things to keep in mind. If you are planning on diving with Nitrox, we recommend avoiding high-pressure aluminum tanks such as the AL 100 or 3300 PSi neutral buoyancy or compact tanks. Instead, opt for a high-pressure steel tank that can handle Nitrox up to 3442 PSI.

Paints and Coatings

Aluminum tanks are available in a wide variety of colors, whereas steel and small aluminum tanks are available in a limited selection of colors due to small and erratic production runs.

Despite the availability of colored aluminum tanks, it seems that most coatings seem to encourage corrosion in aluminum than prevent it. Furthermore, modern paints do not seem to be as durable as coatings in previous generations, and soon you will find them peeling and flaking. If water manages to make its way beneath the paint, it can begin to corrode the tank. Darker coatings may even obscure corrosion beneath the paint, whereas clear or translucent colors highlight any corrosion. However, we generally recommend avoiding paint on aluminum.

For steel tanks, this is less of an issue assuming they receive proper care. Keep an eye out for any deep scratches that have cut through the galvanizing and exposes the bare steel underneath. It should be touched up with a cold-galvanizing compound or a rush-inhibiting paint.

Regardless of which type of scuba cylinder you own, there will always be some kind of cosmetic imperfection even when it comes fresh out of the factory. These imperfections will only become more numerous as you take it out on dives. With minimal care, all tanks should last for years regardless of their cosmetics. If your main concern is on how the tank looks rather than how it performs, then you need to rethink your priorities. Consider renting tanks instead of owning.

Accessories

It is very rare for scuba tanks to come with a handle or net, however they can be purchased separately if you really want them.

The benefit of handles is self-explanatory and it makes heavier steel cylinders easier to carry on land since they tend to weigh more. Cylinder nets are typically made of mesh and their purpose is to protect the finishing on the tank as well as reduce corrosion of booted tanks.

Despite these benefits, these accessories come with a serious downside. The reason being, they are a snagging hazard when you are diving, and there is a serious risk of getting trapped underwater. For this reason alone, many veteran divers refuse to dive with these add-ons because the downsides far outweigh the benefits.

Brands

Only a handful of companies manufacture scuba tanks for the US market, and Catalina and Metal Impact are a couple of US based ones. Luxfer is yet another name to know, though they have stopped manufacturing aluminum cylinders in the US. We’ve noticed some Chinese manufactured AL80 tanks exported for the US market under the name Cyl-Tec. The Italian manufacturer Faber makes steel tanks for the US under the XS Scuba and Blue Steel brands, as well as its own.

There are little to no differences in quality between these scuba cylinder manufacturers. Of course, that is because they must all adhere to DOT specifications and each tank must pass testing and inspection by an independent agency.

We have found that Metal Impact cylinders tend to be more readily available at lower prices with the same high-quality as Luxfer and Catalina. Furthermore, veteran divers tend to prefer Luxfer over Catalina because their cylinders provide better trim characteristics and buoyancy for stage and sidemount applications. With that said, we found Metal Impact cylinders to have equal and sometimes even better buoyancy and trim than Luxfer. Lastly, Faber is the only manufacturer of galvanized steel scuba tanks.

General Care

Whether you choose a steel or an aluminum tank, you will need to maintain it well so that it will last a long time and function as intended. To that end, you should follow standard safety practices when handling them.

To begin, never leave a scuba tank standing. Make sure it is placed flat on the ground when not in use.

Next, do not try to fit incompatible valves with a 1st stage regulator. You can purchase an adapter in case you have a yoke tank with a DIN reg. On the other hand, yoke regulators can only handle 232 bar of pressure, and DIN tanks 300 bar, so it is highly dangerous to attempt to use them together. You can fill the DIN tank up to a maximum of 232 bar and use it with a yoke adapter, however this is risky and not recommended.

If you have an aluminum tank, perhaps your main concern will be the exterior of the tank since it is more susceptible to damage. If you own a steel tank, your priority will be the interior because you don’t want there to be any internal corrosion.

Lastly, all scuba tanks should be subject to a visual inspection once a year, and a full safety inspection (VIP or hydrotest) once every 5 years by a certified technician in an authorized service center.

How to Maintain Your Scuba Tank

A steel scuba tank can last up to 15 years through multiple safety inspections if you are taking proper care of it. How do you make your scuba tank last that long? Follow the steps outlined below. Scuba tank maintenance is vital if you want to prevent catastrophic failure and avoid endangering your life on a dive, so we highly recommend you perform these steps.

First, completely rinse your tank with freshwater after each dive, particularly if you’ve been diving in saltwater. Salt causes corrosion, so make sure to rinse thoroughly to keep grit from clogging the tank valve which would make it difficult to control the air supply if left unchecked.

Second, never store your cylinder when it is completely full or empty. It should always have some pressure in it to reduce the chances of internal contamination. Additionally, a fully pressurized cylinder may eventually crack. Store the scuba tank in a tank holder if possible or and make sure it is stored upright.

Next, make sure to rinse the regulator with fresh water as well. Let everything fully dry before placing it in storage. Also make sure the boot is removed during storage. Keep in mind that you should never leave scuba equipment in direct sunlight. The UV rays will deteriorate the materials, causing them to fade, weaken, and crack.

Lastly, scuba tanks must also pass certain safety inspections. We talk more about this in the FAQ section below.

Frequently Asked Questions

How long does a full tank last?

You can expect a full tank to last approximately 45-60 minutes. This is assuming the diver is an average open-water certified diver using a basic AL80 tank diving 40 feet down. However, this number is highly variable depending on a number of factors.

To start, the size of the cylinder affects its total air capacity, so a larger tank will provide a longer supply of air. However, having more air does not necessarily mean one will last longer underwater. You must also consider how deep you will dive.

The deeper you dive, the more atmospheres (ATA) of pressure there is which reduces how long a tank of air will last. Every 10m (33 ft) underwater increases the pressure by 1 ATA. With that in mind, starting at 0m there is 1 ATA of pressure and at a depth of 20m (66ft) there is 3 ATA worth of pressure. The air inside the tank gets compressed by the water pressure, so with 3 ATA of pressure, the air in the tank will only last ⅓ of the time at depth compared to 1 ATA of pressure.

Next, your level of physical fitness affects how much air you consume. As you swim, your muscles use up oxygen and your heart rate increases. You will feel the need to breathe larger breaths at a faster rate to replenish the oxygen in your body. If you are unfit, you will use up the air far faster than someone who is physically fit. That is why it is important to do cardiovascular training if you would like to have a longer bottom time.

In general, if you are diving casually at a depth less than 10m (33ft), using a standard size cylinder, it should be quite easy to make the tank last up to an hour or more. If you dive any deeper than that and you are also unfit, then the dive can be as short as 20 minutes. Professional divers are experts at controlling their movements and buoyancy to lengthen their bottom time as much as possible.

How much does it cost to fill a scuba tank?

The cost to fill your tank depends on your location and how much the local dive shops are charging. Generally, you can expect to spend around 10-15 dollars to fill a tank with a capacity around 3,000 PSI. Some dive shops may charge as low as five dollars to fill a tank. If you are unsatisfied with what you are being charged, you can shop around to get a better deal.

How often do scuba tanks need to be tested?

Scuba tanks are under strict regulation and they must meet the U.S. Department of Transportation’s (DOT) requirements for inspections. All scuba cylinders must be subject to two forms of inspection: the Visual Inspection (VIP) and the Hydrostatic Pressure Test (a.k.a. The Hydro Test). A licensed inspector must perform these tests at a US DOT approved testing facility. These tests are to ensure that tanks that have been in use for many years are still safe to use.

Visual inspections are conducted yearly and are given a sticker to indicate that it has passed inspection and when the next inspection is due. To be clear, the sticker expires on the first day of the month shown on the sticker.

In the US, hydrostatic pressure tests are conducted every 5 years. Your tank is considered expired on the last day of the month shown. When purchasing a tank, you must look for the sticker and hydro retest mark to ensure that they have not expired.

Any tank that has been visually inspected within the last 12 months, and hydro tested within the last 24 months, is considered recent. Thankfully, all scuba tanks sold must have already passed the first DOT certification and the yearly VIP. Furthermore, dive shops will not refill cylinders that have expired or have not yet been tested.

Closing Remarks

When purchasing a scuba cylinder, consider what your budget is and your diving plans for the future. Steel scuba tanks have an excellent lifespan and superior buoyancy characteristics, making it the optimal choice for most divers. When purchasing a steel tank, look for a hot-dip galvanized steel tank in a capacity that meets your needs even when it is underfilled. This solves any short fill concerns you may have.

If your budget is tight and you don’t plan on diving as much in the future, then aluminum has much lower initial costs. When shopping for an aluminum tank, choose a brushed finish and stay away from paints. Find a tank with a convertible valve with a 200 bar DIN outlet with K-insert. This is often abbreviated as ‘Pro DIN/K valve’. Unfortunately, the standard AL80 tank with K-valve is not an all-purpose tank. You may have to own several scuba tanks to maximize your diving enjoyment.

Last update on 2024-03-20 / Affiliate links / Images from Amazon Product Advertising API