Humidity problems

evelyn1984

Member
Hi,

I have just switched to flower a week ago and need to get my humidity down and am having real problems. i bought a dehumdifier and put that in my grow tent and on full power it is still 53 with the light on and slightly more when the lights off. i live in an old house where the humidity is naturally high around 60% so i know this could be an issue. i'll outline my current set up below and if anyone can offer any advice that would be great.

1 x 1.5 x 1.5 x 1.8 grow tent within a large room (4 x 4 meters)
1 x 600w HPS
1 x 5inch ruck fan and rhino filter for extraction (currently extracting into the room where the tent is set up, im looking to send this into loft or under floor boards, which is best?)
no intake because its such a small tent (so im pulling in air through the vent thats within the room via the extraction)
300w dehumidifier
SMSCOM fan speed thermo controller
small oscillating fan

i cant really open any windows because it is at the front of the house and its winter here.

when i turn up my extraction to get the humidity down the temp drops too much.

should i move the dehumidifier to the main room just outside the tent and dehumidify the whole room rather than just the inside the tent? what causes humidity (science)? should i put a small fan outside my tent by my inlet vent to help cool the air being sucked in by the extractor?

any help would be greatly appreciated.

Thanks Evey =D
 

Slipon

Well-Known Member
53% is`t that bad atall, actually more or less perfect ..

I would try to use it outside the tent and see if I could get the RH of the entire room down if anything, and use a fan inside the tent, even with a high RH in flowering you can avoid mold and Mildew by keeping a good air circulation ..

IMO between 40% and 60% is perfect all grow and I would fist begin to worry if it was over 60% in flowering and less then 30% in Veg.
 

evelyn1984

Member
Hi Slipon,

Im definitely going to try dehumidifing the whole room, thanks for the info on RH and what works. ive just been going off what i heard so if im safe with 53 that will do for me. =D

Im going to sort out where im pumping my warm air too, cant be good feeding it back into my main room where the tent is.

Thanx Evey
 

Slipon

Well-Known Member
well some say 40% in flowering and some even go as low as 30% but 50% is nice, as I said just keep some nice air circulation going and do keep a eye on white spots/mold aso. tho I still do that no matter what, that and all other kinds of bugs and other problems, male flowers aso. we try to avoid

like I said, I would fist begin to worry if it hit +60% or maybe even +70% and take actions, same in Veg. most say 60-70% is best but 40-50% work just as good, just need to water more often and/or mist em a bit as seedlings, under 40% I would maybe try with a bowl of hot water to get it up but a humidifier would fist be sumthing I would look in to if it got close to 30%

ps

RH follow temperatures as a rule of thump the higher temps the more air the more moist it can hold, but it also depense on a lot of things

about your intake/outtake, sure to "reuse" old air/co2 is not the best thing you can do, so I would try to run some dutching either to get rite of the old hot air and/or to "collect" fresh

I run a pice of 6" left over dutching from my 600W cool hood, from one of my two passive intake holes to my hallway (just out side my spare bed room my grow room is located in) to "collect fresh air (can easily be removed in 2 sec if somebody knock on my door) as I can keep some fresh air flow and lower temps in my hallway, specially near the floor as hot air travels up and cool falls down, my hot air I just let out to the spare bed room tho (up high)
 

evelyn1984

Member
thats awesome Slipon, thanks for all the info. i think im going to run some ducting from my intake into a seperat more ventilated room so when the extractor pulls it pulls fresh air in. think that will help lots. im not too worried anymore though now i know im good with mid 50's.

Thanks again =D
 
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