Having humidity jump when lights go off. Tenpin my tent at night are low 60s in my tent and seem to be 3-4 degree less than out side which I think is weird? But humidity jump up to 90 with lights out . Is this because of dew point. Just starting to read about the vpd but it drop with the increased humidity . I did just adjust exhaust fan to run at 75 humidity and it’s dropping it some . What’s everyone’s thoughts
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Just a side note I doing a batch of photo and light are 12/12 this last week and temps have drop this week 10degree out side . Future batch’s will be all autos to keep temps steedy thru the cold months I’m inside insulated work shop no heat. So will do a 20/4 cycle ?
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Yes dew point, relative humidity is relative to temperature. You may need to find a way to safely utilize a small desk top heater to dry the air maintain temperature, make sure the tent floor isn’t too cold. You can always set the tent on a 2inch piece of foam board.
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True out side temp is 67 and humidity is 91 dew point 65
My pots are off the floor and my building is warmer than my vivosun control panel says my tent is colder than the building is and humidity is much less in the building even with the zipper open about 1/3 at the top
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Not really an ideal situation unfortunately, you normally don’t want to see more than a 10 degree drop from day to night. 80 at lights on 70 at light out at most.
Night time conditions are still very important, plants still grow at lights out and can become stressed and harder to bounce back when the lights come on. Not to mention mold grows great in the dark.
That VPD number is essentially how well the plant can breathe through its leaves, moving gases and water/nutrients. For seedlings ideal night-time VPD is around 0.8 kPa. For cannabis plants in veg, the ideal night value is around 1 kPa. In bloom a night-time VPD around 1.2 kPa is typical.
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Dehumidifier, vice heater (unless below zero Centigrade).
Dehumidify and creates some heat.
I run one 24x7, in my lung room, with direct connected to grow tent tent
Currently a gallon of water a day. PNW Seattle been raining, this month.