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Importance of cycling air during seedling stage

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    Importance of cycling air during seedling stage

    Hi guys, I would like to know how important is to cycle the air in a grow tent during the seedling stage?

    I'm trying to keep my tent in optimum conditions for seedling with a temperature of bout 73-77F, relative humidity of 68-72% for a VPD of about 0.6-0.8.

    With such a high RH, my humidifier plugged on an external humidistat is almost running constantly and I need to refill it twice a day. My exhaust fan is programmed to run when the RH goes above 72%. In my current conditions, my exhaust fan runs for about 30 seconds and off for about 45-60 seconds while the humidity goes back from 67 to 72%.

    I do have a 6" oscillating fan running to move the air around. Since my seedling are barely using any CO2 and I have one 6" x 18" air intake port open in the tent, I was wondering if it's even worth it to run my exhaust fan?

    mmxk I'm in the same place with my seedlings right now; I have a humidifier going and a small heater in the grow room. I keep the fan going in my grow box to keep the air moving.
    Anyone can grow mid grade weed easy. If you want to grow top shelf bud, study hard.

    Growing since July 21, 2016; smoking since 1967
    2 BCNL Roommate hydro boxes w/ 400w COB LEDs, Future Harvest nutes

    Grow # 17: Box 1: Germination Aug. 1, 2022
    Future 1 Anesia Sds (37%thc), Imperium X Anesia Sds (36%thc)


      I would definitely keep small fans on your plants , when I'm forcing the sex of a regular seed I use a tote to cover the seedlings to have near 100% humidity this is only for a week but it has not hurt them ,so I think you can leave it closed except when you are working on them
      new grow room built summer of 2017 ,argo max tent for veging ,big kahuna reflector, 1000hps with added leds for the full spectrum . 15th indoor grow ,5 years outside gorilla grows(stealth is the key),veg under t5s growing autos under 300w leds
      current grow


        I just cut a water bottle in half and put it over the seedlings to increase humidity. I never turn off exhaust fan and i dont worry about humidity until flower where it can cause issues. I keep seeing things about VPD but never have i payed attention to it. I've had seedlings grow fine in 30% rh.


        • alltatup
          alltatup commented
          Editing a comment
          What's VPD?

        • Tersky
          Tersky commented
          Editing a comment
          It stands for "Vapor Pressure Deficit"
          It is basically another way to look at humidity except it takes temperature and air saturation into account. If i were doing large scale commercial agriculture then i might pay attention to it but for small scale grows like we do then rh is adequate.

        • oldjarhead100
          oldjarhead100 commented
          Editing a comment
          good idea plastic bottles ,I went with a turned over tote for forcing sex and I use a tall pollination tray for clones

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