45% humidity veg & flower?

HerbGlaze · Mar 31, 2018

If you have air evenly distributed through out the canopy then you can run it up to 70%, running that right now and have zero mold. Strains are a huge variable too, some can be much more mold resistant then others.

My grow area isn't in a insolated area so it's naturally cold and humid. Set up a dehumidifier in the room along with 3 Damp Rids outside the tent. Humidity and temperature can be a c*** to dial in

heatherlonglee · Mar 31, 2018

Telling the OP that he can go to 70% or even 60% humidity is just poor advice. You're only here for the pissing contest; not really giving this guy help. This is dudes FIRST grow! Get through a few indoor flowering seasons, then let dude try to raise his humidity. Yes you can grow successfully at higher humidity, just don't come and state it like everyone should be doing it and it's so easy; thats just a wasted post so you can sound cool or whatever other reason you wanted to add to your post count.

stoned40yrs · Mar 31, 2018

jidoka · Apr 1, 2018

heatherlonglee said:
Telling the OP that he can go to 70% or even 60% humidity is just poor advice. You're only here for the pissing contest; not really giving this guy help. This is dudes FIRST grow! Get through a few indoor flowering seasons, then let dude try to raise his humidity. Yes you can grow successfully at higher humidity, just don't come and state it like everyone should be doing it and it's so easy; thats just a wasted post so you can sound cool or whatever other reason you wanted to add to your post count.

I am trying to help. Your old school bro science is his problem. Increasing veg humidity (not saying late flower) would instantly help

bsgospel · Apr 1, 2018

Right? Dudes gotta get some reps in on dialing in a room/space.

heatherlonglee · Apr 2, 2018

Lat time again jidoka this is OP's 1st grow! Don't make it seem like this is easy to go 70% humidity. Acting like it's so easy to go high humidity in veg, or whenever; again that's exactly what you shouldn't be saying (I'd gladly dump negative rep on you if still possible) going high humidity is for advanced level growers. You coming in here acting like it's for everybody makes me wonder if you just get away with high humidity; but know nothing? He knows very little about problems that could develop in the space he's growing in, it's his first time! Let this guy sort out whatever other problems will arise and be better prepared to handle them knowing pm isn't the problem. If anything goes wrong plants get sick new growers end up chasing their tails trying to find the problem. He's on his first grow there is going to be problems stop trying to trojan horse/sabotage dudes grow!

This growing good weed stuff is so easy I swear these other fools around don't wan't good real info shared. Just turn it into a pissing contest and share poor misinformed info in a way that helps nobody but themselves.

jidoka · Apr 2, 2018

I can tell him the problem low humidity will cause. Lack of transpiration will prevent the plant from moving Ca through the xylem to new growth. The plant will start building cell walls with K instead of Ca. That will practically guarantee pest/disease.

I know this works cause a lot of CO commercial grows agree with you. Granted they have plenty of other problems but cranking humidity up with misters always helps

Plus if you do actual tissue testing in CO you will learn the avg grow has 1% Ca and 7% K...a recipe for problems

But yea...maybe I am purposely trying to make the ops life harder. That is a problem with the internet

jidoka · Apr 2, 2018

For the pics or it did not happen crowd

Edit...btw dump all the neg rep on me you want, ask your friends to help. No fucks are given by me. I never bothered to know what that is even about

heatherlonglee · Apr 2, 2018

jidoka read the damn thread! Stop making useless generalizations that a new grower will not be able to use! OP has stated that his humidity is around 45% and at it's highest around 60%. That's not low humidity! Your'e repeatedly saying stupid stuff; your post count has risen congrats. :tiphat:

bsgospel · Apr 3, 2018

I don't think it's useless or a generalization. It got pretty specific when he started dropping tissue % numbers and xylem pathways as a function of plant health. OP wanted to know if 45% was cool, they found out they could go higher with stability (or even, that it's not the end of the world if it happens to go over 50)

A generalization would be: you'll mold that sucker out with more humidity because..."new grower" ....?

:ying:

slownickel · Apr 3, 2018

Pushing RH up is not that hard to do.

What folk don't realize is that PM is not caused by high RH. It is caused by the swing in the RH. More than a 15% swing on most varieties is the kiss of death and all kinds of disease will show up, especially if the plant had bad nutrition. Getting Ca uptake is everything in agriculture.

Doka knows the importance of Ca, having this plant in a stressed situation due to low RH is not good.

The situation needs to be evaluated a bit more.

Why is the RH that low to begin with? What if any equipment do you have available?

Pans of water on the floor could help, but I would be worried about the peaks and valleys of RH first....

slownickel · Apr 3, 2018

Chrono2 said:
for starters id like to say about 25-28 days in, my plants look healthy and are on par size wise with other day by day grow videos of auto flowers. (especially considering this is my first grow ever)

now for the main question can i veg and flower in 45% Rh? has anyone had SUCCESSFULL grows in these ranges give me any input? 43-50% RH is the average for my tents (lights on, and about 50-60 lights off) and tbh i dont want to add a humidifier or dehumidifier if i dont HAVE to, but everyone reccomends my rh be alot higher in veg :\

The key is the swing. If you are at 45 and regularly hitting 60 RH, you are at the threshold of PM or some other rot. If you can raise that 45 to say 55 and then push the upper to say 65 or so, that would probably help.

Your RH is not impossible to work with. It is just that your plants would be a lot happier (scientific term) at a higher RH. Just be careful what you wish for.

More than 15% RH swing is asking for problems. Lots of literature out there that proves this. Lot of literature also blames high RH for PM and is dead wrong. Even in the scientific world there is a lot of garbage information.

PaulieWaulie · Apr 3, 2018

Chrono2 said:
Thx for the reply mate seems i might be just worrying over nothing, think ima buy a humidity controller and see how that works maybe save some electricity and get better yields

There is definitely a sweet spot for VPD with your temp and humidity. But I think unless every aspect is dialed in on your grow, your not gonna see that benefit too much compared other issues you could focus on if your just beginning.

PaulieWaulie · Apr 3, 2018

slownickel said:
Pushing RH up is not that hard to do.

What folk don't realize is that PM is not caused by high RH. It is caused by the swing in the RH. More than a 15% swing on most varieties is the kiss of death and all kinds of disease will show up, especially if the plant had bad nutrition. Getting Ca uptake is everything in agriculture.

Doka knows the importance of Ca, having this plant in a stressed situation due to low RH is not good.

The situation needs to be evaluated a bit more.

Why is the RH that low to begin with? What if any equipment do you have available?

Pans of water on the floor could help, but I would be worried about the peaks and valleys of RH first....

Both times that I have gotten PM my Lights off Humdidity has hit 60s RH. I would say lights on it was 50%. So a swing of only 10. Which would seem pretty common considering the temp change of 10 degrees C being common.

Why is the swing itself the culprit you think ?

slownickel · Apr 3, 2018

PaulieWaulie said:
Both times that I have gotten PM my Lights off Humdidity has hit 60s RH. I would say lights on it was 50%. So a swing of only 10. Which would seem pretty common considering the temp change of 10 degrees C being common.

Why is the swing itself the culprit you think ?

Here is what the BASF guys compiled. They usually do a good job...

https://betterplants.basf.us/news-&...-featured-stories/managing-powdery-mildew.pdf

I imagine in almost all the cases, humidity spikes immediately after lights are turned off. The walls can often sweat from excess moisture and the same thing happens on the leaves. May not be running off, but most definitely highly localized humidity.

Then of course, many still do such a bad job growing the plant, induced toxicities of Mg, Fe and Al and at the same time have a lack of Ca, Cu, Zn, Mn and others.

Don't guess at humidity levels. Realize that a measuring device on the wall has little to do with the RH under canopy.

Some folks have mixes that are often anaerobic down deep and hold too much water. This also makes for weak tissue.

Then of course there is genetics. Some genetics are much weaker than others and much more susceptible. There are a bunch of factors that lend themselves to the perfect storm...

Avenger · Apr 4, 2018

Periods of high humidity and relatively low temperatures at night are prime conditions for powdery mildew conidia to germinate and form chains or threads of spores that protrude from the leaf surface and are visible. Then the lights come on and the RH tanks and drys everything out. Perfect conditions for powdery mildew dispersion. Poof, spores in the wind, ready to land and begin infecting new tissue this evening when the RH spikes again. :peacock:

fuck it up enough to let the plants surface temperature reach the dew point and free water to form and you will meet downey mildew too.

But if you routinely spray fresh water on the plant you can help kill powdery mildew spores.

Absolem · Apr 4, 2018

PaulieWaulie said:
Both times that I have gotten PM my Lights off Humdidity has hit 60s RH. I would say lights on it was 50%. So a swing of only 10. Which would seem pretty common considering the temp change of 10 degrees C being common.

Why is the swing itself the culprit you think ?

Hey Paulie,

I'd be curious what your temperature swing was from lights on/lights off when the pm reared.

slownickel said:
What folk don't realize is that PM is not caused by high RH. It is caused by the swing in the RH. More than a 15% swing on most varieties is the kiss of death and all kinds of disease will show up, especially if the plant had bad nutrition. Getting Ca uptake is everything in agriculture.

Agree.

Cool. Just added to my post count.

jidoka · Apr 4, 2018

1st grow absolute best thing to learn is how to get Ca in the plant. Do that and the entire rest of your grow life just got easier. Don’t do that and get ready for one bro science cure after another

If you don’t want to humidify how do you feel about foliar spray?

heatherlonglee · Apr 4, 2018

slownickel said:
Some genetics are much weaker than others and much more susceptible. There are a bunch of factors that lend themselves to the perfect storm...

OP doesn't know his strains! OP doesn't know what pm looks like! OP is on his first grow! Op has more than one tent going! OP has multiple strains running; again first time with these strains ever! Perfect storm of idiots is coming for the OP. lol

Straight knowledge here!

PaulieWaulie said:
There is definitely a sweet spot for VPD with your temp and humidity. But I think unless every aspect is dialed in on your grow, your not gonna see that benefit too much compared other issues you could focus on if your just beginning.

Chrono2 · Apr 4, 2018

thank you for all the replies everyone appreciate it!
unfortunately i dont have a few reps worth of time to practice with
got my humidity controller yesterday and am keeping the room at about 56-62 at all times right now, no more than a 7% swing (in reality its more like 3%, but as soon as my exhaust fan turns on it spikes by about 2-3%, i think thats just an odd offset of the room getting alot smaller when the fans turn on, bumping the % humidity up)

i also have 2 16" inch fans oscillating directly on the plants, canopy temperature is around 22 C

45% humidity veg & flower?

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