Humidity and lighting question

From a fellow grower: In late stages of flower using high intensity lighting supplementing it with CO2 assuming all other parameters are ideal during the lights on should relative humidity be increased to 70-80 alone with heat to 85 f so the plant can take the 1500 ppm of CO2 than returning to 40% RH an hour or so moisture can evaporate before lights out.

During late stage flower that would be too much humidity and could cause some bad things to happen to your colas. Humidity should be in mid 60’s with temps in the mid 80’s.
Check this VPD chart and use accordingly.


that chart is a great tool. I use it everyday.

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Another good VPD Chart, however I like the one that @LateNightGardner linked a bit more…might start using that one


Yep, I got it on the forum a while back. Been using the past month.

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