Humidity help

Hi, with the temperature outside getting warmer I'm struggling juggling my humidity, when I have my extraction fan on temps are around 23 degrees with lights off but if I have my humidifier on temps get to around 25 degrees, but humidity struggles getting below 55%, if I turn my extraction fan off humidity drops to around 40% but temps junp to about 30 degrees so my extraction fan is just counter acting my humidifier.
Anyone have any advice?

The extraction fan is powerful for the tent it sucks it all in so I'm thinking even if my humidity is a little high I might be fine as the stale air is gone.

So what stage of growth are you in? Veg or flower? Veg can take some humidity, maybe as high as 80%. Flower should be in the 50's.

Sorry I'm into my 5th week of flower

MustGro said:

So what stage of growth are you in? Veg or flower? Veg can take some humidity, maybe as high as 80%. Flower should be in the 50's.

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Would you say any range in the 50s is doable for flower?
If I keep my dehumidifier on full strength I can keep RH well below 50, but temps go up by about 4-5°, making my tent slightly too warm for my liking 82~85°. If I keep the humidifier on low, I can keep temps to around 78~81, but RH can get up to 55. Wondering if you think the 55 range is too much for flower.
Sorry if I hijacked your post OP

Username85 said:

Would you say any range in the 50s is doable for flower?
If I keep my dehumidifier on full strength I can keep RH well below 50, but temps go up by about 4-5°, making my tent slightly too warm for my liking 82~85°. If I keep the humidifier on low, I can keep temps to around 78~81, but RH can get up to 55. Wondering if you think the 55 range is too much for flower.
Sorry if I hijacked your post OP

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If you are running LED lighting plants like warmer Temps to about 85 and not past. In the 70s for LED is to cool for alot of strains can cause stress. That's what I've heard.

Newgrower2021 said:

Hi, with the temperature outside getting warmer I'm struggling juggling my humidity, when I have my extraction fan on temps are around 23 degrees with lights off but if I have my humidifier on temps get to around 25 degrees, but humidity struggles getting below 55%, if I turn my extraction fan off humidity drops to around 40% but temps junp to about 30 degrees so my extraction fan is just counter acting my humidifier.
Anyone have any advice?

The extraction fan is powerful for the tent it sucks it all in so I'm thinking even if my humidity is a little high I might be fine as the stale air is gone.

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For you man you said humidifier to bring temps up but that also will raise your humidity. Have you looked into a dehumidifier? That lowers humidity, you never want to have your exhaust fan kick off. And your tent sucking in is bad to, you never want alot of negative pressure nor to much positive pressure. I heard a little slightly pos pressure can keep pest away, but told a slight negative pressure is best if you want the smell to exit where you are exhausting too. I would looking the Ac Infinity Inline fans with the Bluetooth 67 controller. It's a blessing to have. Good luck!

I meant dehumidifier

I'll look at the rest though thanks

A constant amount of water vapor in the air will show as different relative humidities depending on the air temperature. So if the temp goes up, the air can hold more moisture, resulting in a lower rh because that same amount of moisture represents a smaller percentage of what the air can actually hold. If the temp goes down, the air can hold less moisture, so it registers as a higher rh because it represents a larger percentage of what the air can hold. This is why your humidity goes down when your extraction fan turns off, because the air temp rises when youre not extracting.

Honestly, the conditions you described arent that bad, totally manageable. I find with led the best temps for me are around 27-30°c, rh in the low to mid 60's. In early flower i have gotten away with temps around 32°c 75% rh, but later in flower this is not ideal and the plants prefer slightly cooler and drier conditions. I would suggest looking into VPD (vapor pressure deficit) and consulting some VPD charts to find the best humidity levels for your normal operational temperatures. Instead of combating high temps, i normally adjust the humidity levels to get the proper vpd at a higher temp, but you have to spend some time watching the dials to get a feel for how conditions change so you can sequence your extractions properly.

Newgrower2021 said:

I meant dehumidifier

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I've got the same thing going on atm, I need the dehumidifier but it's summer time and 24/25c during the dark period, there's only 1.5/2c between night and day.
I've got a fan speed controller to keep the fan running slowly and continually during the dark period to keep fresh air going through and also keep down the temperature, when the lights come it turns up the fan to cooling speed.

All of the time I've grown its been 50/65% in my tent 50% being rare 55/60% being the ave and I've not had rot problems in years.

A fan speed controller can be picked up for £10.

Star Dog said:

I've got the same thing going on atm, I need the dehumidifier but it's summer time and 24/25c during the dark period, there's only 1.5/2c between night and day.
I've got a fan speed controller to keep the fan running slowly and continually during the dark period to keep fresh air going through and also keep down the temperature, when the lights come it turns up the fan to cooling speed.

All of the time I've grown its been 50/65% in my tent 50% being rare 55/60% being the ave and I've not had rot problems in years.
View attachment 4939163
A fan speed controller can be picked up for £10.

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That makes me feel better. I’m trying to keep temps on my lower side which means less dehumidifier. I’m using LED, and I know they aren’t known to be problematic with higher temps, but I don’t want to tempt anything so close to chop. Think I only have 2-3 weeks left and I have to finish strong lol

I really got into trouble with humidity in the northeast last year late in flower before i had good AC in my grow room. Decided to flip the cycle over to keep the lights on at night and off during the day. I just flipped them in one day and the plants seemed fine. That made it a little easier to control temps and humidity. Also gotta watch out for RH spikes when the lights go out and the tent cools down. Now I run AC during the day and dehumidifiers at night.

Username85 said:

Would you say any range in the 50s is doable for flower?
If I keep my dehumidifier on full strength I can keep RH well below 50, but temps go up by about 4-5°, making my tent slightly too warm for my liking 82~85°. If I keep the humidifier on low, I can keep temps to around 78~81, but RH can get up to 55. Wondering if you think the 55 range is too much for flower.
Sorry if I hijacked your post OP

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I wouldn't go below 50%; I shoot for 55% in flower. They can take 60% no problem until the buds get bulky. You just need to keep the conditions dry so they drink fluids and you definitely need to keep bud mold and powdery mildew at bay. I've never had a problem in flower running 55-60 up to say week 5 and then trying to keep close to 55% the last month or so when the buds fatten up.
That help you any @Newgrower2021 ?

Even on a good day the uk is damp lol, we're barely 100 miles wide and in the middle of the Atlantic, it's no surprise its so humid.

I've not seen below 85% for a few weeks and it's been up in low 90s it's been a difficult few weeks.
I've also changed to night time running it's worth 4/5% humidity to me, still not ideal but better.

Star Dog said:

Even on a good day the uk is damp lol, we're barely 100 miles wide and in the middle of the Atlantic, it's no surprise its so humid.

I've not seen below 85% for a few weeks and it's been up in low 90s it's been a difficult few weeks.
I've also changed to night time running it's worth 4/5% humidity to me, still not ideal but better.
View attachment 4939549

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Eastern Canada so it's humid here too. 90-95%RH every morning outside all summer and fall when the dewpoint hits at dawn; but we run closer to 60-70 most days without rain. I'm developing a pretty good dehumidifier and AC collection between the grow and dry/cure rooms.

I don't see it as irrelevant since the gulf stream that keeps you warm comes from here (east coast of NA) and keeps us warm and moist too. -30c is a REAL cold day on the "Rock" (NFLD); I think you'll find their winter temps average closer to 0c. I don't know about Moscow.
It could all be irrelevant to @Newgrower2021 though unless they live in one of these places, blimey....
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