The General Setup for a Tank Based CO2 System
The pressure in a CO2 tank is around 1200 psi. In order to run CO2 tanks, you need a pressure regulator. The regulator will step down the pressure to about 50 psi, so it can be managed by the solenoid valve. Some regulators have two gauges, in which case one gauge displays the tank pressure while the other displays the release pressure.
Tubing is strung above the tops of the plants and run to the solenoid valve. The tubing has many microscopic holes in it, which allow the CO2 to be evenly distributed through the garden. As carbon dioxide is released, it sinks down into the plant canopy because it is heavier than air. An oscillating fan placed on the ground will help keep circulating the CO2 through the plant growth.