Without measuring the actual leaf temp is there a ballpark anyone can help me with for my room. Running two 300 watt led @60-80 percent. I’m sure it’s a guesstimate but it’s set to zero now.
I don’t know if this will help, but I modified a DLI Chart when using VPD as I grow photos indoors and usually veg longer than any of the charts I have seen. I do not measure leaf temp offset.
and here is the VPD chart I also modified based on currently published charts you can find online.
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Thanks but I guess my question is how to set the leaf offset because if I set it to zero it’s vastly different than set to -2.
For 30.00 bucks you can get the AC Infinity temp gun. And be dead on.
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I guess mine to be -2. No real specific data to back it up. Just read that number was common for LEDs.
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I went neg 2 as well.
That is interesting. Not sure I’d trust the RH & air temp readings though, depends on how quickly it could accurately grab them from around the leaf being measured. Because I find that I have only a few seconds after opening my door to accurately measure leaf temps, before the ambient air rushing in starts to quickly affect the leaf temp. And my RH/air temp sensor that I hang in that general area definitely doesn’t react as quickly. So I’m guessing that the gun may have the same issue with air temp & RH, but I don’t know. But I think that an IR gun for leaf temps is a no-brainer if someone’s on their second or third grow & plan to keep going. They’ll be able to accurately calculate your leaf vpd if they also can measure the air temp & RH around the leaf being measured, also they’ll know what their leaf temps are & can shoot for an optimal range there, & they could try to adjust their leaf vpd. ( I like that they made ‘air vpd’ much smaller than ‘leaf vpd’ on the display, since ‘air vpd’ is not the target to be adjusted.) They will be less likely to go off-track following bad numbers or bad practices. Also it’s handy to have a temp gun around the house. I use mine for all types of things.
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