Dose what the crop can use
Enrichment only converts to yield when light is available to drive photosynthesis. The CO2 dosing unit scales its target concentration with measured PAR and pulls back automatically when vents open past the point where the gas is simply being exhausted.
Distribution beats capacity
Growers often add capacity to solve a distribution problem. Perforated layflat tubing laid along the row delivers gas into the canopy where the stomata are, which usually raises effective concentration more than a larger source ever would.
Safety
Ambient CO2 is monitored independently of the dosing measurement, with audible alarm and automatic shutdown well below any occupational limit.