I am new to the Pulse community and I am trying to wrap my head around the VPD.
I am utilizing CO2 at a level of around 1500 ppm. My daytime temperatures usually range around 85° With a leaf temperature of 82°, However VPD chart indicates humidity levels to be above the normal 60% which usually is taboo to go over.
I was wondering if someone would be able to help explain if I should be over 60%, or stay under 60% not allowing me to achieve the proper VPD.
I haven’t read anything about not going over 60% humidity when growing cannabis but, based having read quite a bit of bro science over the past few years, I suspect that it’s because of the concern about mold or mildew.
The Pulse indicates what heat or humidity is needed to hit a given VPD target so I’d follow the guidance. In terms of warding off mold and mild, take steps to ensure that the grow area has air flow.
If you’re growing in a tent, put a fan at the canopy level. If you can get an oscillating fan in the tent, that’s great. If not aim that fan toward the center of the canopy.
If you’re in a grow room, make sure that the room is well ventilated and set up fans to keep air moving around the plants.
If you don’t defoliate heavily, it wouldn’t hurt to have air blowing beneath the canopy, as well.
Was just watching this Bugbee video. At the 33:00 minute mark, he talks about the role of Si in plant nutrition and states that adding Si to plants can help eliminate powdery mildew.
Just thought you might want to check it out.
Welcome to the community @DTpaws5. First I just want to let know, if you don’t already. That John from Pulse just launched a new "Big User’s Guide ".
A few days ago, you should definitely check that out for any information, about the Pulse, you are looking for.
Although I agree with @oc_grower, about the air flow.
I would follow the recommendation of the, Pulse Pro. Which I believe gives you the choice to, 1: Lower your Temperature, or 2: Increase your Humidity.
Personally I would lower the temperature, and depending upon how low it has to go to get it to the VPD. You may be able to do that with just running your fans.
With in reason, no matter how you get to the correct VPD, I would most certainly do what ever it takes to accomplish the correct VPD.
“May Your Plants Dance”
if you’re using CO2, you need to be at a higher temp like 85 (which is good), and yes higher temp means high humidity. High humidity means you’re at risk of mold, so if you’re supplementing CO2 you pretty much need to be doing preventative treatments for mold, which is a whole 'nother topic.