Vpd

You need to pay attention to the plants first and foremost. VPD can help guide you, because every plants going to have its own subtle ideal. but in general, if you are running high c0s than theoretically your ideal VPD would increase because you need to run he light at more intensity which requires higher humidity as well. You get to a point where the heat gets too hot and the stomata of the plant close, then photosynthesis stops.same happens if you have lack of co2. If you are running extra c02 in those ranges some people get in the upper 80s. Water uptake by the roots is going to change more than you should change humidity.you want her to be drinking from the roots. I would do what 001100010010011110 said and not change your target VPD too much. Just pay attention to your plants, they should be able to tell you what they need. it just gets hard to do if you change multiple things at one which it necessary when running extra co2. You may be able to find a few charts or videos of people out there and general numbers. A lot of the videos i have found are a little old with people using slightly older tech and sealed rooms which can be a little different than tent growing for sure.

Maybe? VPD impacts rate of transpiration which impacts rate of drinking, and rate of drinking impacts your optimal concentration of fertilizer provided. (higher vpd = lower EC and vice versa). You shift one around, the others must jive with it or it'll be out of balance and you'll run into symtpoms within days-to-months. (closer to optimal, the longer it takes to see symptoms) Is it better to adjust VPD or overall concentration of the nutrients provided? I am assuming you are in a soilless or hydro context if supplementing CO2. Unless there's some reearch on it, you absolutely cannot trust the human eye on this and 10x so given a small numer of planys with varying genetics as your sample from which to draw conclusions. Just the fact of the matter. That doesnt mean someone won't be incredible confident about what they believe is true. Without real evidence to back it up be skeptical. I'd stick to your typical VPD ranges for stage of life cycle and adjust your fertilizer formula as needed to avoid deficiencies or toxicities... dial it in until you find that goldielocks zone for vege / flower and whatever else for which you want to have a unique formula. I find 2 (vege and bloom) is enough, but YMMV. You need temperatures at a higher range to maximize CO2 / rate of photosynthesis. When this stuff oscillates under normal conditions, people have traditionally adjusted fertilzier to match and not the other way around, but that doesn't mean it is 'best to do.' It might correlate, though. In the end i doubt you can tell a different no matter what you choose to do. It all has to jive with growth... it's still a matter of observing and adjusting fert formula as needed.

Depending on the stage at which your plants are, you can go up to 1050ymol/ms with the CO2 content from 1200 to 1050ymol/ms and increase the temperature bias to 30 degrees, then the plants metabolize the CO2 very well. The vpd value is responsible for the growth of the plants due to the transpiration of the leaves. Increase the temperature should lower the relative air spruces. There are tables where you can read the ideal vpd value for each stage, which is calculated by room temperature and humidity.

Hello- vpd is just temperature and humidity. CO2 might affect humidity, but if you’re already controlling you’re good. CO2 benefit is more PPFD. CO2 helps photosynthesis. VPD is just transpiration. I believe you do need higher temperature to take advantage of the CO2 for photosynthesis though. So match your humidity to the target vpd with that ideal temperature.