I just received a 9oz CO2 bottle for free. It is a paintball CO2 canister. Would this be sufficiant for use in a CO2 setup? And what other equipment would be needed? Any and all help would be greatly appreciated. I currently have a DIY yeast system.
It really depends on the size of your aquarium. For example, for a large (i.e. 90g) tank, a 9 oz CO2 tank would run out within a few days. For a smaller, 2.5g nano tank, for example, it may be OK.
Keep in mind that the prices of CO2 tanks do not rise linearly with their sizes. For example, I would pay the equivalent of 70 USD for a 5 lb tank, but a 10 lb tank costs 80 USD. A 20 lb tank costs 120 USD.
Also, refill costs are the same (for me) regardless of tank size.
As for other equipment that will be required, you will need a regulator and a needle valve, at the bare minimum. Another high priority piece of equipment is a check valve, to prevent a possible back siphon of water from destroying your regulator. Other optional equipment include a bubble counter, a solenoid, a diffuser and a drop checker (with a 4 dkH reference solution).
If you decide to get a standard CO2 regulator with the CGA320 fitting, you will also need a CGA320 to a paintball canister adapter. This will also allow you to switch to a regulator CO2 tank if you wish to upgrade the size in the future.