Best Scuba Tank Buying Guide

Scuba Tanks (Cylinders) Basics

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Buying vs Renting

Before you purchase your scuba tank, consider if renting would be a more practical option.  

• Typically, renting costs only slightly more than refilling a tank. If most of your diving takes place at locations reached by air, traveling with scuba tanks becomes impractical. Most dive charters include tanks and weights in their packages.
• Many scuba divers prefer renting tanks to avoid maintenance hassles. The downside is that rental shops might run out of tanks, especially during busy diving weekends.

There are circumstances where owning your cylinders might be more beneficial than renting.

• If the ideal cylinder size for you is not commonly available for rent. Most shops typically rent standard aluminum 80 cuft tanks.
• Your dive center is far from home, making frequent trips for rentals both time-consuming and costly.
• Owning your own dive gear, including your preferred tank type and size, offers unmatched convenience and satisfaction.

How many tanks do you need?

• Most divers choose to purchase 2 tanks, since typical dive trips involve at least two dives, and most dive boat charters schedule two-tank dives. Owning more than one tank saves you the trouble of renting a second cylinder.

What size tanks do you need?

• The right tank capacity varies for each diver and their needs.
• Tank capacity is typically measured in cubic feet. Most recreational divers find tanks between 80 to 100 cft sufficient. Aluminum 63 cft tanks can be suitable for younger or shorter divers, providing enough gas for a safe dive.
• Larger divers often have higher gas consumption rates due to their size. Consequently, they may prefer tanks with greater capacity, and their physical size allows them to manage larger tanks.
• Estimate your gas capacity needs before buying a tank. If you're unsure, renting different sizes a few times can help you gauge your requirements.

Steel vs. Aluminum

   

Understanding the differences between steel and aluminum tanks helps in making an informed choice.

   

• Steel tanks offer similar capacities to popular aluminum models, with some having significantly larger volumes, up to 149 cft, and higher pressure ratings.
• Because steel is heavier than aluminum, divers using steel tanks generally need to wear less additional weight.
• Aluminum tanks tend to stand upright without a tank boot due to their design but might make divers more tail-heavy.
• Conversely, steel cylinders are often praised for their excellent fore-to-aft trim balance.

The most significant difference between the two is: Steel cylinders can rust, while aluminum cylinders cannot.

• Moisture in an aluminum cylinder may cause minor oxidation but generally won't lead to severe damage. Even with salt water, the corrosion is minimal.
• In steel cylinders, however, even a small amount of moisture can cause significant damage quickly, especially with salt water, possibly leading to irreparable conditions if left unchecked.

High Pressure vs. Low Pressure

If you prefer steel tanks, the next decision is between high-pressure and low-pressure options.

• Steel high-pressure and low-pressure tanks may appear similar in size but contain different amounts of air. 
• High-pressure tanks typically require a DIN regulator setup. If your regulator is yoke-configured, it may need conversion to DIN.
• High-pressure tanks often require more frequent maintenance, especially their valves and O-rings, compared to low-pressure tanks.
• Moreover, high-pressure steel tanks have a higher likelihood of failing the 5-year hydrostatic inspection compared to their low-pressure counterparts.

When choosing a tank valve: DIN, Yoke, or Both?

Link to ABYDA

There are two types of fittings for attaching a regulator's 1st stage to the tank: DIN and Yoke.

• Yoke couplings are more common worldwide, often found on standard aluminum 80 scuba tanks.
• DIN fittings are considered safer and are ideal for high-pressure tanks, preventing high-pressure O-rings from protruding as with yoke fittings.
• DIN-style tanks can use yoke adapters for filling, and yoke-style tanks can employ DIN adapters for the same purpose.
• Regulators might have adapters that allow them to switch between yoke and DIN configurations. Such adaptations should be done by qualified scuba repair technicians.

Newer tanks offer Din/Yoke pro valves, allowing conversion by simply removing or inserting a plug.

Inspection and tests

Though not mandated by the USA DOT, diving industry standards recommend an annual visual inspection based on observations from the National Underwater Accident Data Center.

• In the USA, tanks must undergo a hydrostatic test every five years, and newly manufactured tanks are stamped with the date.
• Dive shops in the USA will require a current VIP sticker within the year and a hydro stamp within five years before filling your tank(s).

Different countries have various regulations, and some tanks are made for specific regions.

• Ensure any scuba tank you purchase is properly marked for use in your intended country.

This is crucial, especially when buying a used tank. Filling stations are obligated to inspect these details and may refuse to fill non-standard or out-of-date tanks.

Nitrox Scuba Tanks  

There are two basic types of breathing gases available to sport scuba divers. 

Normal Air ― Air is filtered and compressed into your tank. Always get your air fills from a Certified Pure Air Station.

Nitrox ― Nitrox comes in various oxygen blends requiring specialty training and certification to use.

• Pure oxygen, based on the Nitrox mix, is added to an O2-clean tank and blended with filtered air to reach the desired pressure. Nitrox can be safer due to less nitrogen, thus extending bottom time.
• Always get Nitrox fills from approved blenders and personally analyze each fill.

• A tank filled with Nitrox must always be clearly marked to prevent accidental usage without the necessary precautions.

 

If you're not Nitrox certified, consider it for safer diving experiences. Check out our Continuing Education Courses. 

Pros and Cons of Gas Grills

Gas grills are a popular choice for outdoor barbecuing due to their quick heating, ease of use, and relatively minimal cleanup.

Charcoal grill enthusiasts may prefer the smoky flavor of coals over gas. However, many gas grills now include options to add charcoal or wood pellets for enhanced flavor. Hybrid or combo grills can accommodate both gas and charcoal grilling, though not always simultaneously.

Gas grills are typically more expensive than charcoal grills. They offer heat control via knobs, reaching temperatures between 400 and 600 degrees Fahrenheit. Maintenance or part replacements, such as burners, valves, vents, or heat shields, may be required. Common materials include stainless steel, cast aluminum, and porcelain-coated steel. 

For more information, please visit Double Aluminum Gas Valve.