This is the chart I’m attempting to stand by. Anyone else know of this one? Is so what’s your thoughts on it? What do you think is the best chart to go by?
Yup.
Although to properly know your VPD one needs an IR temp gun to get your leaf surface temperature. This is entered to a VPD. Chart and it will spit out the correct values.
Oh sorry I use this one for F but I’m in C so I use the one posted above
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Yes an mines is on the way I just try to stay in a good zone til it gets here
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I’ve grown with the standard chart for two years… Seems to work close enough. I didn’t bother with a ir gun. Many don’t even grow within VPD levels but I can tell you it sure helps growth!
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First time seeing that Celsius chart
Yea this is my first grow an I’ve been using that chart without the ir gun but can’t wait to get it. It seems to be getting me up to my first month so far lol
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A view from the other side.
I’m not a big fan of new growers trying the follow any VPD charts, can get in trouble quickly trying to keep your RH over 70 or 80 as the charts might suggest, opens you up for more problems like powdery mildew, mold and bud rot. Keep your RH anywhere between 40-60 and you’ll be fine in veg and early flowering and then get it as low as you can for last few weeks of flowering to avoid the harvest destroyer that we call bud rot.
For commercial growers with closed/sealed grow rooms and perfect environments and safe guards like air snipers (to destroy mold spores and such), they benefit nicely from following VPD and using CO2, home growers - not so much, will have much less problems with a RH under 60 (and under 50 in late flowering).
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I think I might try the 40%-60% I have trouble with high rh when light is off but can control it when lights on 65%-76% rh
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Would under 70%rh be ok without my humidifier on I’ve seen it as low as 54% rh when lights on
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I don’t really pay a whole lot of attention to VPD charts either. Anything between 50 and 70% is good for veg, but if it goes outside that briefly I don’t worry about it. I try to reduce it to 30 to 40% in flower, but I do crank up my dehumidifier the last few weeks of flowering (20 to 30%.)
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Need to keep exhausting the tent when lights are off to keep RH down, that’s when most of the damage is done - during the night with high humidity.
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Ok so I can turn my humidifier off but I notice when I do my temps reach 82 max when lights on wont that cause heat stress
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Nothing wrong with 82F but should be able to get it cooler with running a little more exhaust if desired.
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82 isn’t all that bad. I won’t worry about my temp unless I am getting sustained temps above 85.
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My temps max out early morning at 85 and any more than that I have to get dressed and see what’s going on. Most of the time I’m in the low 80’s right towards the end of lights on.
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Yea I’m learning as I go some days the RH be 63% when lights off some day’s be 76% when lights off
Be higher then the temperature in my tent when light’s off but I’m getting it right
This where it stays around 54%-67% when humidifier is off an lights on. So should it be lower when light’s off?
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