However, co2 is not ideal. The filling process is fiddly, the cylinder has to be drained, chilled and filled to a specific weight
Compressed air is easier, and can be filled at sites that run on air for free when you play or shops at a set price per fill (and you probably need to bring an adaptor for a paintball cylinder)
Note that if you regularly get fills at a dive shop then financially it's better to get a dive cylinder and fill station. Fill the dive cylinder at the shop to get more air per fill and then get a fill station to self fill your paintball cylinder
Tom, thanks for your post. I have a 20 oz. paintball tank fitted with a special valve that I attach to my Sodastream. Sodastream CO2 bottles are expensive, this is a much cheaper alternative to getting CO2 than from Sodastream. In the USA where I used to live, it was easy, cheap and convenient to get my paintball tank filled with CO2. Now I find in the UK that it's much more difficult. Is it possible to get my paintball tank filled with CO2 somewhere? A dive shop, or a gas supplier, or...?? Homebrew supply?