Looking at various VPD charts, seem keeping it in the green would be much higher RH at my temps than recommended RH from what I have read. Does the same curve apply during flower as veg? Right now on the chart I am at 78F and says my VPD should be like 8.4 @ 70% RH, isn’t that high? Later in flower I will drop temps(hopefully) to about 68F and then it says my RH should be @65% for VPD of 8.2? I’m confused??? I thought lower RH during flowering?
VPD during flower?
- Thread starter vikesinja
- Start date
calvin.m16
Well-Known Member
Been playing with this a lot lately since I'm running almost all known to me genetics. Here's my 6 light rooms environment stats from the last 90 days. My results have been great keeping it an average of 1.3 vpd apparently. I learned when you push 1.5+ VPD things can start slowing down or plants can show signs of stress.
I try to keep my humidity in the 55-60% range and temps in the 75-80 °F range in flower, in veg I will run my temps 80-85 with 60-65% humidity.
I try to keep my humidity in the 55-60% range and temps in the 75-80 °F range in flower, in veg I will run my temps 80-85 with 60-65% humidity.
compassionateExotic
Well-Known Member
your cemented things in that don’t work based on vpd, meaning look at fall when it drops temps and also plant is at its peak of maturity it’s suggested to lower rh, but also lower temps. Based on temps being lowered it would be in correct vpd.
when I am in veg-mid flower my heat in room is 78-82f canopy temps with vpd at 1-1.3 and rh at 60-75% rh.
when mid flower-end I lower temps but also ppfd of light and co2 all based on lowering temps. At final weeks I’m even under 70f and trying to get as cold as I can but also following vpd . this is why at end u can easily do 45-55% rh and it’s not bad
The Ultimate Vapor Pressure Deficit (VPD) Guide
"Why devote an entire guide to VPD?" you might ask. The answer is that the vapor pressure deficit (VPD) is extremely important for growing plants. VPD helps you identify the correct range of temperature and humidity to aim for in your grow space. With VPD you can achieve the best results while...
pulsegrow.com
This chart is different than the one I was referencing and seems to be more in-line with what I would expect in terms of RH-temp-VPD. Thank you, I will use this instead.your cemented things in that don’t work based on vpd, meaning look at fall when it drops temps and also plant is at its peak of maturity it’s suggested to lower rh, but also lower temps. Based on temps being lowered it would be in correct vpd.
when I am in veg-mid flower my heat in room is 78-82f canopy temps with vpd at 1-1.3 and rh at 60-75% rh.
when mid flower-end I lower temps but also ppfd of light and co2 all based on lowering temps. At final weeks I’m even under 70f and trying to get as cold as I can but also following vpd . this is why at end u can easily do 45-55% rh and it’s not bad
The Ultimate Vapor Pressure Deficit (VPD) Guide
"Why devote an entire guide to VPD?" you might ask. The answer is that the vapor pressure deficit (VPD) is extremely important for growing plants. VPD helps you identify the correct range of temperature and humidity to aim for in your grow space. With VPD you can achieve the best results while...
