So, there have been a lot of threads (it seems) lately regarding pressurized CO2. Hopefully, this primer will help alleviate any fears that people have when starting to delve into CO2 as it can be quite intimidating at first. In addition, hopefully this primer will answer some of the most commonly asked questions regarding pressurized CO2.
As this thread will be discussing how to set up a pressurized CO2 system, advantages/disadvantages of using a pressurized setup versus a DIY (yeast) CO2 system will not be discussed in this primer. For more information, please take a look here:
On to pressurized CO2!
First, when people refer to pressurized CO2, we often read that we will need a "regulator" or a "regulator build." What does this mean exactly? This term is thrown around quite loosely in the aquarium hobby, but a pressurized CO2 system consists of more than just a regulator.
Here are the essential components you will need:
1) A CO2 cylinder
CO2 cylinders come in various sizes. They are often used in paintball guns (usually sold as 20 oz cans). They also come in 2.5, 5, 10 and 20 lb sizes (larger sizes such as 50 lb tanks do exist, but they are quite large and bulky, and are not commonly sold outside of specialty applications).
CO2 tanks come with a fitting known as a CGA320 fitting, which is standard in North America. Europe and Asia use different industrial standards. Paintball tanks, however, do not come with this fitting, and come with a pin depression type valve. More on this will follow below.
Many people believe that getting a small, paintball CO2 tank is "cheaper", however, this is not usually the case. Regulators (see below) often come with CGA320 fittings (or can be adapted to such). However, as paintball tanks do not contain this CGA320 fitting, normal regulators cannot be used, and you must purchase either a special regulator with the required fitting, or look around for a paintball tank to CGA320 adapter (often, quite difficult to find). In addition, refill costs for CO2 tanks are generally not much different. The refill cost for (say) a 5 lb tank and 10 lb tank may only be a few dollars different. For example, I can get my 10 lb tank refilled for $17.50, while a 20 oz paintball tank may cost $5 to refill. This means that the cost per pound of gas is more for a smaller tank. In addition, the larger the CO2 tank, the longer you can go without refilling the tank, etc. It can be quite a hassle to drive out and refill the tank, depending on where you live. The general piece of advice is to get the largest tank that you can afford and/or is feasible for the space that you have.