RH issue

[Elwindo]

Hi everyone !
Here's my first post on this wonderfull forum.
I'm in my 4th grow so still learning...
Plus this is my first grow indoor and i'm worried by the Rh in my tent...
I'm in week 8, 5 plants (4 fastbud : bludreamatic, bubblegum, wog, gsc and 1 sweet seeds cream mandarine xl) the buds become interesting but i can't have a better RH than 63 to 70...
Are my Girls in danger ? Did some of you have success even with this situation ?
I've got carbon filter and exhaust fan, 1 clip fan and yesterday have add a deshumidifier that doesn't seem to make the job...
Thx for your replies and cheers !

 

[Olderfart]

Hi everyone !
Here's my first post on this wonderfull forum.
I'm in my 4th grow so still learning...
Plus this is my first grow indoor and i'm worried by the Rh in my tent...
I'm in week 8, 5 plants (4 fastbud : bludreamatic, bubblegum, wog, gsc and 1 sweet seeds cream mandarine xl) the buds become interesting but i can't have a better RH than 63 to 70...
Are my Girls in danger ? Did some of you have success even with this situation ?
I've got carbon filter and exhaust fan, 1 clip fan and yesterday have add a deshumidifier that doesn't seem to make the job...
Thx for your replies and cheers !

That is a tad high for flowering, but with air circulation, you may get away with it. Is your extraction fan is turned all the way up? If you can't get the RH lower, air circulation is your friend. Make sure that you get good air movement throughout the canopy, and if necessary, that means trimming the canopy if it is dense. I like at least one fan moving air up top, and another one or two at pot level stirring things in the lower canopy.

In future, if the RotBlock/Phyter tests going on now are positive, get some RotBlock to treat the plants with so you reduce the risk of mold.

Good luck with it.

 

[armanidog]

Does your residence have air conditioning?
I have an old house in NE Georgia, I have a mini-split AC. Right now the RH outside is 99% (just had some showers last night and this morning).
Inside the hygrometer says 53%.
I found this chart, I cannot say if it is accurate or not.

As Olderfart said trimming leaves (especially towards the bottom of the plant) and air movement will really help

 

[Elwindo]

Hello guys ! Thanks for your responses ! I'll try to trim and find another fan or two...
About trimming, at this stage of flowering, couldn't it be harmful for the plants ?
@Olderfart i did already see this post of the test... And will follow it for sure

 

[armanidog]

Hello guys ! Thanks for your responses ! I'll try to trim and find another fan or two...
About trimming, at this stage of flowering, couldn't it be harmful for the plants ?
@Olderfart i did already see this post of the test... And will follow it for sure

This is a good video. I defoliate as the plant grows. I like to be able to see across the bottom third of the plants with no leaves in the way.

 

[Elwindo]

Thx for the vid @armanidog

 

[Elwindo]

Hi everyone !
I found this on Alchimia that made me think i wasn't so much in trouble...
Can it be shared or does not it worth a thing ?

Vapour pressure deficit (VPD) in cannabis cultivation

Temperature and relative humidity play an important role in indoor marijuana cultivation since much of the plant's activity depends on these factors. Incorrect values of these two parameters will result in an invalid VPD (vapour pressure deficit), which will in turn result in poor plant...

www.alchimiaweb.com

Cheers !

 

[tronN00dles]

Hi everyone !
I found this on Alchimia that made me think i wasn't so much in trouble...
Can it be shared or does not it worth a thing ?

Vapour pressure deficit (VPD) in cannabis cultivation

Temperature and relative humidity play an important role in indoor marijuana cultivation since much of the plant's activity depends on these factors. Incorrect values of these two parameters will result in an invalid VPD (vapour pressure deficit), which will in turn result in poor plant...

www.alchimiaweb.com

Cheers !

Yeah from my understanding, RH alone doesn't really tell the whole story. In general, 40-60% is a good "safe zone", but we can be a bit more specific if you incorporate temperature and look at overall VPD.

I use this one myself: https://vpdchart.com/

That one allows for a differential between air and leaf temp. I typically assume my leaves are 2 degrees cooler than the air temp. Anyway, if you're pushing 65% in say, mid flowering, you’d just want your temp to be as high as possible without crossing over into the danger zone. I try to stay under 28C, some people stay stay under 30C, etc. I’m sure someone cleverer than me will chime in with the actual number lol.

Anyway, if you can safely bump up your temperature a bit, you can use something like a small space heater to “burn off” some excess humidity. Typically when my humidity is a little high, I’ll put a small ~250W watt heater outside my tent and point it toward my intake. This is usually enough to bump up the temp a couple of degrees and drop the humidity a few points as well. If I were to put it directly in the tent, I’d exceed my safe temp threshold so I tend to keep it outside.

I also have a small portable dehumidifier in my tent, but to be honest, I don’t think it does much lol. I should look for a better one.