@Wannabe @Bulldognuts concerning CO2 enrichment:
It’s true that our indoor environments are generally ~25% below optimal photosynthesis due to CO2 levels. I can’t emphasize enough that in order to achieve optimal photosynthesis indoors one needs a comprehensive plan which maximizes PPFD, maintains ideal leaf surface temperature, and seals the CO2 into the space.
At a molecular level, cannabis absorbs and transforms CO2 and H2O to form C6H12O6 (sugar). These molecular processes are sensitive to temperature and light energy; when temperatures are too high, RuBisCO (an amino acid) bonds to oxygen instead of carbon, and the affected molecules are lost through photorespiration. It’s an enormous waste of the plant’s time and resources. If there’s an excess of light energy (PPFD) the plants simply waste the energy, unless the energy is so great it kills chloroplasts and bleaches the plant. CO2 concentration, leaf surface temperature, PPFD, and percentage of potential photosynthesis are all inextricably linked.
Earth’s atmosphere has an abundance of CO2(>400ppm in 2020), as far as C3 plants like cannabis are concerned. Ventilation can supply the grow area with enough CO2 to support a “reasonable” PPFD. Atmospheric CO2 isn’t capable of supporting 100% of the plant’s photosynthetic potential, but my understanding is that the only risk is we over-light the plant and waste money. I do not know if an excess of light will cause RuBisCO to bond to oxygen to the detriment of the plant’s growth. Conveniently, LEDs are more efficient at lower currents, so we can potentially dim our lights to match the limited CO2 in the air.
CO2 enrichment is useful if you’re looking to maximize output per plant, and can provide a tightly sealed grow area with an excess of 500 PPFD; however, unless you seal in the CO2, it will diffuse into the atmosphere. If you are ventilating your tent while the lights are on, the CO2 levels will seek equilibrium with the fresh air. I’m trying to be precise, but I’m basically saying this example wastes CO2 and money. I’d like to note that CO2 isn’t required during the scotoperiod in cannabis, so ventilate your dark grow rooms, please.
If you have a sealed grow room and 1200 PPFD at 79F LST, then CO2 enrichment is going to give you that additional yield. I hope my explanation elucidates that there’s a cost-benefit to CO2 enrichment.
Lastly, I don’t judge anyone for spending their own time and money on a bag of mushrooms or a fermentation. You aren’t hurting me, although even small increases in CO2 levels are detrimental to human wellness. I hope this information empowers and informs your decisions growing forward.
@dbrn32 @MattyBear @Myfriendis410 let me know if you see any errors in my argument, or can enhance this in any way.