Humidity to high?

[Waira]

First of all, there's nothing automatic about getting bud rot, it's entirely possible to have high RH% through bloom and avoid it,.... but the potential is much greater, and that's a damn scientific fact ...Soil is NOT the usual source of the cause of botrytis, it's primarily windborne, and unless you have a HEPA filter in the room, it's already there-- yes, including the soil (unclean dirt is a non sequitur dude), but it's not sporing out in there, that's not how that organism rolls.... Sorry, but your lone, highly limited, statistically insignificant experience does not an axiom make,.. every bit of info on this from quality books to advise/experience from commercial growers to hobby growers is in direct contradiction to your conclusion, easily validated with some 101 level research,...
As for high RH and VPD, what are you talking about? No good VPD chart calls for "high" RH% through blooming, especially late bloom when rot is most likely to set in.... 60% isn't that high, and is in OK zone IF the temps are high enough, but upper 60's is getting dicey... these charts are good reference, not dogma....that said, in the upper 70's to low 80's prime T zone, the recommended RH% is well out of 60's RH%...... keep in mind higher temps suppress the activation of the spores... Several other things factor in here, perticularly a strains vulnerability to rot, bud density, air movement,....

Although a different living organism, introducing bought clones into the grow space can also introduce pests, according to many posts I've seen.

WTF?? ... while it's true, why did you even put this in here, it's beyond irrelevant,.....
....point is Simplicio, this isn't the first time you've come into the Infirmary with what I'll charitably call mixed quality info, is it,... some of it very bad in fact, which Staff won't tolerate in this part of the forum,.. you want to express your opinion, take outside of Sick Bay,....members are in a tough position here as is, adding conflicting or bad info is unacceptable...

 

[Simplicio]

First of all, there's nothing automatic about getting bud rot, it's entirely possible to have high RH% through bloom and avoid it,.... but the potential is much greater, and that's a damn scientific fact ...Soil is NOT the usual source of the cause of botrytis, it's primarily windborne, and unless you have a HEPA filter in the room, it's already there-- yes, including the soil (unclean dirt is a non sequitur dude), but it's not sporing out in there, that's not how that organism rolls.... Sorry, but your lone, highly limited, statistically insignificant experience does not an axiom make,.. every bit of info on this from quality books to advise/experience from commercial growers to hobby growers is in direct contradiction to your conclusion, easily validated with some 101 level research,...
As for high RH and VPD, what are you talking about? No good VPD chart calls for "high" RH% through blooming, especially late bloom when rot is most likely to set in.... 60% isn't that high, and is in OK zone IF the temps are high enough, but upper 60's is getting dicey... these charts are good reference, not dogma....that said, in the upper 70's to low 80's prime T zone, the recommended RH% is well out of 60's RH%...... keep in mind higher temps suppress the activation of the spores... Several other things factor in here, perticularly a strains vulnerability to rot, bud density, air movement,....


WTF?? ... while it's true, why did you even put this in here, it's beyond irrelevant,.....
....point is Simplicio, this isn't the first time you've come into the Infirmary with what I'll charitably call mixed quality info, is it,... some of it very bad in fact, which Staff won't tolerate in this part of the forum,.. you want to express your opinion, take outside of Sick Bay,....members are in a tough position here as is, adding conflicting or bad info is unacceptable...

If I'm supplying "bad info" then I don't like it any better than you do, and actually appreciate being told.
But advice that goes against the majority view is not necessarily bad advice.
I don't think it's bad info to believe that dirt is at least slightly riskier than hydro for bud rot because some spores might hide in dirt that can't hide in a water system.

I suspected that the advice about bud rot was questionable in a hydro system with good air circulation, so I decided to experiment.
Certainly, high humidity increases the chances of infection from microbes, but by how much?
If the probability of bud rot increases from 0.01% to 0.02% from high humidity during flower, then I'm doubling my chances of getting it, but don't really care.
If it increases the chances from 10% to 30%, I'd certainly change my ways.
But who really knows? I could find nothing about bud rot probability in hydro or soil, just universal warnings to keep humidity low.
In some scenarios, fear of bud rot might harm yield, if VPD guidelines optimize bud growth.
If that's true, then risking rot might be worth it.

My bottom line is that I believe that bud rot warnings are overblown in hydro, and might even harm yield.
So far, my small sample size of 5 tries using high humidity during flower has produced no rot.
Not worrying about it makes growing life easier.

 

[Learninggrower]

Ok well my rh is about 70, tempthe last few days has been high at about 32c, ppm I’ve lowered to 800 on my one plant and 1200 on the other. My ph has been dropping a little to about 4.9 but I’ve been keeping it at about 5.6.

 

[Waira]

..hmmm, well the T and RH% are in OK range, meaning there's decent transpiration going on,.. this is about the flow of nutes/water from roots up, as the leaves transpire water away, they "draw" up from the roots,... Your pH drifting is an issue though! And the res' temp, what's that? I think you have your problems coming from there, as it doesn't take much drift to cause lockout/uptake issues in hydro,...

..... still looks mainly P defc, related, but this advanced, others are in play too but masked some by the P defc.,.... I'm not a hydro' guy, but your res' temps need to be waaaay lower than what your ambient air T is,.. low 70's, upper 60's I believe is best ....