Finding the right refillable mini scuba tank can give you greater comfort and peace of mind during your drives. The Catalina Pony Bottle and the Spare-Air 3000 3.0 are two popular choices.

Catalina Pony Bottle Tanks with Pro Valve

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Spare-Air 3000 3.0 Kit

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Both tanks are rated for 3000 psi and designed to last for years, but there are several important differences. If you need a new mini scuba tank, compare the pros and cons of the Catalina and Spare-Air.


The Catalina Pony Bottle Tanks are equipped with a Pro Valve and available in variable sizes. While it does not come with a regulator, it offers several features that make it an effective back-up tank:

● Available in 6, 13, or 40 cubic feet sizes

● Nitrox ready up to 40%

● Includes the Pro Valve 

● Compatible with both yoke and DIN valves

● The aluminum tank is rust resistant

With this pony bottle, you get a solid spare tank that works with yoke or DIN valves. The aluminum-alloy cylinder is also resistant to rust and allows oxidation, adding a protective coating that helps prevent corrosion.  

The main benefit of the Catalina refillable mini scuba tank is the variety of sizes. You can choose from 6, 13, or 40 cubic feet. 

Before using this tank, you will need to add a few items. You need a holster to secure the tank to your buoyancy control device (BCD) and a regulator. As the tank does not include a refill adapter, you need to get it filled at your local scuba shop. 


Customers tend to agree that this is a reliable spare tank. In fact, several customers have used this brand of spare tanks for over a decade and claim to never dive without a Catalina refillable tank.

Another feature that customers love is the Sherwood Pro Valve. It is one of the most highly-rated tank valves and is valued at about one-third of the price of the tank when purchased separately. The valve increases the overall value of the Catalina pony bottle.

One customer complained that the cylinder did not include the nitrox sticker needed for refilling at most scuba shops. However, you can get the cylinder inspected at many filling stations for a small fee.


SPARE-AIR 3000 3.0 KIT

The Spare-Air is a 3000-psi spare tank with three-cubic feet of air. It includes several useful accessories so that the tank is ready to use upon arrival. You simply need to fill it before use. Here is a closer look at the details:

● Three-cubic feet tank with 3000 psi rating

● Nitrox ready up to 40%

● Measures 15 x 5.5 x 3.5 inches

● Compatible with yoke valves

● Includes a refill adapter

● Comes with a holster and safety leash

The Spare-Air uses the yoke valve and comes with a refill adapter, allowing you to refill the tank from any scuba tank with a yoke. You also have the option of filling it with an air compressor at a scuba shop, such as a standard tank.

The included holster secures the tank to your BCD, in front of your body, or onto your primary air supply. It is even equipped with a regulator/mouthpiece.

While the Spare-Air includes useful accessories, it has one major limitation. The three-cubic-foot size is relatively small. 

2.4 cubic feet is often recommended for spare tanks when ascending from 16 feet at a rate of 30 feet per minute. However, customers have used this tank for ascents from 50 feet, with air lasting 2 to 2.5 minutes. While it may not be suited for deeper dives, it is a convenient tank for shorter depths.



Most customers enjoy the size of the tank and mention how easy it is to connect to their BCDs. It is also built to last, with several customers using the same tank for five years or longer. 

Like the Catalina Pony Bottle, one customer had an issue with the inspection sticker. Instead of missing the sticker, the tank had an expired inspection date. If this issue occurs, paid inspections are available.



Both options are suitable choices for adding a spare tank to your diving equipment. You get an extra source of breathing gas in case your primary supply runs out or experiences a malfunction. However, there are advantages to each bottle.

The Catalina works with yoke or DIN valves. You simply use the DIN insert to convert the Pro Valve for use with DIN regulators.

With the Spare-Air, you do not need a compressor to refill the tank. You can use the provided adapter to easily refill the Spare-Air. It is also equipped with its own regulator, unlike the Catalina.

If your existing gear includes a DIN regulator, the Catalina Pony Bottle should suit your needs. However, the Spare-Air comes with a regulator, refill adapter, and holster, making it the more convenient option. Just keep in mind that it is a smaller tank.