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Dehumifier or larger exhaust fan

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    Dehumifier or larger exhaust fan

    Hello my friends, i'm at 5-1/2 weeks into flowering. I have a 3x3x6 grow tent, with a 4" exhaust fan, and three 6" clamp fans in the tent. but with the tent zipped shut the RH stays right around 60%. with the tent open it lower down around 47-52%, but gets a little stinky with it open, and it's still not low enough. my goal is 40%. I bought a small dehumidifier and put it in the tent, it didn't do shit. so what can i do? buy a 6" exhaust fan, the infinity costs about $240, or a larger dehumidifier, about $200, that would go in the room, outside the tent. if I went for the latter, do you think by lowering the RH in the room, it will also lower it inside the tent? your thoughts/experience on this subject, would be greatly appreciated.

    What is the cfm of your 4" exhaust?
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      hello weed Pharma, the CFM is 192. giving the situation a little more thought, the fan has pleanty of CFM for a 3x3x6 tent, but the carbon filter is only 8", do you think changing that to a 14" would pull more air through the fan, and thus lower the RH?


      • Weed Pharma
        Weed Pharma commented
        Editing a comment
        Try running the exhaust fan without a filter and observe what happens to the RH.

      I bought a bigger dehumidifier and placed it near the opening of the intake of my tent - my smaller dehumidifier wasn't doing the job. My RH has now been running in the low to mid 30's and temps around the low -mid 70's -perfect for flowering. here is the one I bought:
      3'x3'x6' Cool Grow Tent and Large Wooden Cabinet
      3 and 5 Gallon Fabric Pots
      Coco Coir with 30% Perlite
      2-450 watt Vipar Spectra LEDs
      4" Exhaust with Vivosun Fan and Carbon Filter
      6" Oscilatting Fan
      GH Flora-Trio Nutes with Cal-Mag and GH Liquid Kool Bloom

      "Why Do You Keep Banging Your Head Against That Wall?"
      "'Cause It Feels So Good When I stop"


        thanks guys,! anyone ever try damp rid, for a short term fix?


          I use a cheap Hisense DH-35K1SJE5 35 pint dehumidifier and use it in the open room that houses the tent. It pulls about 350w and it's kinda loud but it damn sure pulls the water out of the air at a nice rate and that is all that matters to me.


            A lot of growers have discovered that the small dehumidifiers don't work, and so had to invest in larger ones. I have a Frigidaire that's been working great for over 3 years, and it's on during flowering 3 times a year, so around 27 weeks per year. Just make sure to clean the filter for optimum performance and put some H2O2 in the reservoir to clean it about once a year; it can get funky.
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