60-70rh when lights out late flower/ripe

weedstoner420

Well-Known Member
I have my dehumidifier coming on 3-4 minutes before the light goes off to avoid precipitation with the temperature drop, your worst humidity isn't too bad, i get through full grows and don't see under 60% fwiw I've not had bud rot in years.
I've seen you mention running relatively high RH in flower without issues. Out of curiosity is it a constant humidity? Or how much does it fluctuate say when the lights go out?
 

medidedicated

Well-Known Member
Dang, what is the temp and Rh in the room where the tent is? A 20% humidity spike every night would definitely concern me. Running relatively high RH is fine as long as you have proper ventilation, but mold and PM love big swings in humidity.

Did I read that this is an autoflower? Have you tried just leaving the tent door completely open when you off the lights, to see what happens to the humidity then?

It is an auto, but hoping to keep the 18/6 schedule for best growth, I read. Opening the door just swings the temps faster, nothing to humidity with lights on, so figured it would only help less if lights off.

Temp and rh of room is 65-80F sometimes 85F. It is small and well insulated. All these electronics add heat, the dehuey throws the most heat. But rh is what ever I want it to be but preferably 40rh minimum or that room is uninhabitable.

It is a well occupied room so it has to work with me in terms of rh and hot temps, so I burp out the hot air once or twice a day and keep it minimally at 40rh.

Hot air helps, might try it tonight as I have a temp probe for best efficiency without hands on. I got two great heat sources at low watts, 50w and 200w and I think the 50w could handle this but its janky, other is name brand.
 

weedstoner420

Well-Known Member
It is an auto, but hoping to keep the 18/6 schedule for best growth, I read. Opening the door just swings the temps faster, nothing to humidity with lights on, so figured it would only help less if lights off.

Temp and rh of room is 65-80F sometimes 85F. It is small and well insulated. All these electronics add heat, the dehuey throws the most heat. But rh is what ever I want it to be but preferably 40rh minimum or that room is uninhabitable.

It is a well occupied room so it has to work with me in terms of rh and hot temps, so I burp out the hot air once or twice a day and keep it minimally at 40rh.

Hot air helps, might try it tonight as I have a temp probe for best efficiency without hands on. I got two great heat sources at low watts, 50w and 200w and I think the 50w could handle this but its janky, other is name brand.
Yeah, keeping the temp more constant will also help suppress the humidity spike. It's called Relative humidity for a reason - the same amount of water vapor in a given volume of air will result in a higher RH at lower temps, and lower RH at higher temps (to take an example from Wikipedia, 12 grams of water per cubic meter at 86°F is 40% RH, but that same 12 g/cubic meter at 68° F is 70% RH!). So if you can keep the temps from dropping suddenly when the lights go out, your RH will spike less. Hope that makes sense...
 
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medidedicated

Well-Known Member
Yeah, keeping the temp more constant will also help suppress the humidity spike. It's called Relative humidity for a reason - the same amount of water vapor in a given volume of air will result in a higher RH at lower temps, and lower RH at higher temps (to take an example from Wikipedia, 12 oz of water per cubic yard at 86°F is 40% RH, but that same 12 oz/cubic yard at 68° F is 70% RH!). So if you can keep the temps from dropping suddenly when the lights go out, your RH will spike less. Hope that makes sense...
Yea I suspected that was the issue, I used to dim lights for my eyes during feed and noticed the rh jump everytime while temps plumit.
 

medidedicated

Well-Known Member
I tried it! Heater on a timer for 1.5 hours facing intake zipper door opening and the rh only hit 62% maximum! It wroked basically! The temp hit 95F though if that isn’t too high.

Edit: I originally got heat supplement for winter days the leds don’t hold temps at 80-85F for vpd control. I have a nice side light thread going on, which I noticed kept temps nice and high.

Edit: I forgot to check minimum, the minimum rh was 41rh so it kept it more steady too by 4 units instead of 37rh. Now to trial and error how long to keep heater running.
 
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Star Dog

Well-Known Member
I've seen you mention running relatively high RH in flower without issues. Out of curiosity is it a constant humidity? Or how much does it fluctuate say when the lights go out?
My humidity is constantly on the high side 60% on a good day that's with a dehumidifier running (mid/late flower)

The local humidity is a nightmare it's perpetually 85/99% rh.

The fluctuation in the tent over 24hrs is around 7-9% that's gradually over the course of the night with the temperature dropping.
 

medidedicated

Well-Known Member
My humidity is constantly on the high side 60% on a good day that's with a dehumidifier running (mid/late flower)

The local humidity is a nightmare it's perpetually 85/99% rh.

The fluctuation in the tent over 24hrs is around 7-9% that's gradually over the course of the night with the temperature dropping.

It has been similar to me this year, suprisingly for a winter. It is like summer time rh. Small, well insulated room with a legit dehuey works wonders unless you plan on habiting the room under 40rh, shit hurt to breathe IMO.

I could put it somewhere else but would need two of them probably or one running on max or make some other small space unhabitable.
 

medidedicated

Well-Known Member
Freakin dehuey, sometimes it last a couple days, next night it overfills and wake up to 85rh instead of another trial run for improvement.

Got to empty that thing at night for sure sometimes to be safe.

I read that the resin has anti fungal properties which would make sense why I am not screwed yet, but damn I cannot let that keep happening.
 

Star Dog

Well-Known Member
If you don't have a constant drain on your dehumidifier it's simple to add one.
A drill and a 13mm top hat grommet, drill the collection tank put the top hat grommet in then a piece of 13mm tube.
_20230302_235412.JPG
Different application, same thing.
 

medidedicated

Well-Known Member
If you don't have a constant drain on your dehumidifier it's simple to add one.
A drill and a 13mm top hat grommet, drill the collection tank put the top hat grommet in then a piece of 13mm tube.
View attachment 5266119
Different application, same thing.
I went all out and got a nice one, finally, something expensive worth the money lol. It has 35 pints and hose but I see it like this, if I cannot handle that, I could potentially mess up big time if it overflowed.

Practice for maybe next time with a big ass tub and set an alarm. Then again, emptying in incraments has its perks.

edit: some other overflow protection as it is powerfull and unpredictable as it depends on humidity.
 

weedstoner420

Well-Known Member
I went all out and got a nice one, finally, something expensive worth the money lol. It has 35 pints and hose but I see it like this, if I cannot handle that, I could potentially mess up big time if it overflowed.

Practice for maybe next time with a big ass tub and set an alarm. Then again, emptying in incraments has its perks.

edit: some other overflow protection as it is powerfull and unpredictable as it depends on humidity.
I think the intention is that it drains to your home's plumbing return, somewhere that never has to be emptied. For example, mine is in my basement and drains into the sump pump hole. It could also drain into a sink or bathtub. Then you don't have to worry about the collection bucket filling up.
 

medidedicated

Well-Known Member
I think the intention is that it drains to your home's plumbing return, somewhere that never has to be emptied. For example, mine is in my basement and drains into the sump pump hole. It could also drain into a sink or bathtub. Then you don't have to worry about the collection bucket filling up.
That makes way more sense! Interesting, thanks. I tend to read manuals but did not look into anything this time, just plugged in and went.

I glanced over things as needed and was going to when I put it away for a minute. It has an auto timer to clean air filter every two weeks but thats it. It should hold up for a few more weeks.

edit I think I have that too in a basement, I wasn’t sure thats what it was, so thanks.
 

weedstoner420

Well-Known Member
That makes way more sense! Interesting, thanks. I tend to read manuals but did not look into anything this time, just plugged in and went.

I glanced over things as needed and was going to when I put it away for a minute. It has an auto timer to clean air filter every two weeks but thats it. It should hold up for a few more weeks.
Many dehumidifiers have a standard garden hose hookup on the back, but if yours doesn't you can modify there bucket like star dog suggested.

So annoying that they rate these things for x number of pints a day, yet the bucket is always significantly smaller than that...

Edit: nevermind, just thought about how much 35 pints of water would actually weigh...now I understand the reasoning for the small bucket...
 
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