Alright. So either way you go, you'll get a regulator and a bubble counter. Some units come with a selonoid, which I highly recommend as well.
The regulator does just that, regulates the pressure in the tank (which is around 900psi) to a regulated pressure that you can control. I run mine at about 20-25psi. From there, the selenoid will be hooked up. The selonoid allows you to set your CO2
injection on a timer, and have it click off when your lights are off. Since plants don't use CO2
at night, there's no need to run it, it just wastes gas. Out of that you will have your bubble counter and a needle valve. The bubble counter just allows you a visual way to determine how much CO2
is going into your tank. YOu'll hear people talk about BPS, which is bubbles per second. It's just, like I said, a visual way to determine how much CO2
is flowing. The needle valve allows you a finer amount of control to set the exact flow rate you want. Out of the bubble counter is where you will hook up your CO2
tubing to inject it into your tank. This tube you will hook up to whatever diffusion method you choose. Since you have a canister filter, again I'd recommend a DIY CO2
reactor, like the ones you can find guides on in the DIY section. If you use this, you will hook your CO2
line up to that. Or, if you use a different diffusion method, like the one you mentioned in your first post, you will hook it up to that.