unknown water drops on leaves. worried about mold in flower

[Mañ'O'Green]

Your day temps are too low at 72°F and 60% RH.

Where it is on the leaf is weird. Did you move leaves off of it to expose the wet surface? Because it does look like transpiration. If that formed without a leaf over it then it has to be dripping from somewhere. Get your temps up. Keep that air moving.

 

[Waira]

I can say that from what I can tell, it is not guttation. I had guttation on my first ever plant, and it was sappy and almost amberlike in color. This looks like water, smells like water, and tastes like water. I should also mention that this water has never been on more than 5 leaves in a day, and also it is never on more than one leaf in close proximity

Guttation is excess water secretion, not sap really,... comes from the xylem which moves water and mineral nutes, not organics like sugars, proteins etc.,... Buds can exude a sugary sap, often colored amber/red, often mistaken for resin but it ain't! One taste of it will prove that....

..... that said, this water spot isn't coming from the margin teeth where it typically would,... It looks like a drip from above for sure, but from where? Still could be guttation, just not spotted the leaf doing it yet? ....or condensation during dark and higher RH% possibly....
Usually this is more about how wet your medium is, and the plant pumping excess out beyond what transpiration is doing... If your VPD is in decent range, then that's good news, and not related to this directly....

And use the VPD charts as a general guide, not a strict projection... Some are so general that they can be a bit iffy IMO,.. others like above are hyper specific to that Temp difference between leaf surface and ambient air T....
Plants are more flexible than all this, so if things are marginal according to the charts, it's nothing to grind over... Different cultivars and pheno's will also have their own tolerances and performance ranges... Being way off though is cause for corrective actions!
There's a great article and vid (I hope still) in the Reference section on VPD, worth a look-

Food for thought on this: consider an arid climate hashplant in Pakistan, that almost never see's a "perfect VPD range" day in it's life.... ditto for a tropical Sativa marinating in 90+%RH.... true, all these modern polyhybrids are far from their ancestors and less tolerant, but you get the gist...

 

[Orion]

probably way out there with this one but did you check to makes sure there isn't condensation dripping from the top of the tent or anywhere above? The only time I have seen this on my plants is when I am tucking/defoliating and the leaves are overlapping.

This i had happen last grow. Wtf not even running a humidifier anymore. Pretty sure it was from overlapping leaves as you say.

 

[Orion]

Thank you for the compliment!! Yes I'm thinking it may be an infection or something but not sure what. The reason is, it's not on the same leaf. I actually have been removing leaves as I see water on them (only 3-5 leaves a day). I'm really curious though as I've seen this on the internet several times while looking for answers, but nobody seems to know what EXACTLY causes it. It seems to happen with plants that are more Indica like in structure from what I can see online. A commenter below said probably transpiration but I don't see why transpiration would condense unless my VPD got way out of whack, which it has been a perfect VPD pretty much throughout.

Humidity is different in different areas. Hygrometer gives pretty good idea but doesn't tell you rh in between two leaf.
Bad example: when someone makes the sex with someone else, the bodies stay sweatiest in the places where they make contact with other body. Take a reading in between stomachs, whoa 100 rh. Take a reading near the back, probably same as the rest of the room.

 

[ManWithWrench]

[QUOTE="when someone makes the sex with someone else, the bodies stay sweatiest in the places where they make contact with other body. Take a reading in between stomachs, whoa 100 rh. Take a reading near the back, probably same as the rest of the room.
[/QUOTE]
Depends on the position entirely!

 

[Orion]

[QUOTE="when someone makes the sex with someone else, the bodies stay sweatiest in the places where they make contact with other body. Take a reading in between stomachs, whoa 100 rh. Take a reading near the back, probably same as the rest of the room.

Depends on the position entirely!
[/QUOTE]
Yes. This analogy assumes missionary is the standard lol

 

[narmohare]

I have ha

View attachment 1420961

Your day temps are too low at 72°F and 60% RH.

Where it is on the leaf is weird. Did you move leaves off of it to expose the wet surface? Because it does look like transpiration. If that formed without a leaf over it then it has to be dripping from somewhere. Get your temps up. Keep that air moving.

I actually did move one of the leaves in one picture, but the other one was just like that. Just had water sitting there. I have also raised my temps a bit and dropped humidity. Currently sitting at around 73.5F and 55% humidity. This looks to fit better with the chart. I have also just bought some extra fans for air circulation. Hopefully one of these solutions will be the answer I need.

 

[narmohare]

Guttation is excess water secretion, not sap really,... comes from the xylem which moves water and mineral nutes, not organics like sugars, proteins etc.,... Buds can exude a sugary sap, often colored amber/red, often mistaken for resin but it ain't! One taste of it will prove that....
View attachment 1420962..... that said, this water spot isn't coming from the margin teeth where it typically would,... It looks like a drip from above for sure, but from where? Still could be guttation, just not spotted the leaf doing it yet? ....or condensation during dark and higher RH% possibly....
Usually this is more about how wet your medium is, and the plant pumping excess out beyond what transpiration is doing... If your VPD is in decent range, then that's good news, and not related to this directly....

And use the VPD charts as a general guide, not a strict projection... Some are so general that they can be a bit iffy IMO,.. others like above are hyper specific to that Temp difference between leaf surface and ambient air T....
Plants are more flexible than all this, so if things are marginal according to the charts, it's nothing to grind over... Different cultivars and pheno's will also have their own tolerances and performance ranges... Being way off though is cause for corrective actions!
There's a great article and vid (I hope still) in the Reference section on VPD, worth a look-

Food for thought on this: consider an arid climate hashplant in Pakistan, that almost never see's a "perfect VPD range" day in it's life.... ditto for a tropical Sativa marinating in 90+%RH.... true, all these modern polyhybrids are far from their ancestors and less tolerant, but you get the gist...

So this was something I was thinking about. Would it be terrible of me to push the VPD a bit high and have the temps around 72-74 like they are now and drop the humidity to like 30%? This obviously would not be optimal but definitely better than moldy buds. I ask because I feel I'm running out of options here. I have checked for dripping water, in TWO separate tents, I have increased the air circulation, I have given the plant a heavy defoliation twice in the past week so there would be no overlapping leaves, and this is still happening. Maybe worth mentioning 3 other plants lived with this same plant with no issues like this plant was showing. Same environment and everything. Its really giving me a run for my money. This plant is overall pretty healthy other than having water on leaves every morning when I go check on it. Also want to mention this isn't a nighttime only thing. I feed this plant when I wake up, and again a couple hours before lights out (she's a heavy drinker). There's always a couple drops on the leaves at the least.

 

[narmohare]

Go easy on me I'm a new grower (like 4 months experience), but I keep seeing a common theme in this thread which has given me a question. Apparently if two leaves are touching it is likely that there will be water built up there. So as someone who grows mostly Indica plants (short, stout, fat leaves, bushy almost) how do I stop leaves from overlapping? I do defoliation already, canopy management, and LST, but it seems like it would be difficult to make sure no leaves are touching each other. Even my best trained and managed plant (the one pictured in this thread) has at least 20% of leaves that are in contact with another leaf. I don't necessarily think this is why the water is there, as I said in a previous comment I have seen water on the topmost leaves just sitting there, but I am always trying to learn. Is there a way to prevent this water buildup between leaves?

 

[Waira]

:smoking: True, lower RH% is best during bloom which does help keep mold from getting the conditions that kick it off... BUT the cultivar's ("strain", wrongly used in cannabis technically- ) native resistance is very much a big part of this! it run the gamut, auto and photo, from being weak and pretty much indoor/dry only to near bullet-proof outdoor Northern climes super tough!
.. a note: botrytis = grey mold... mildew is another thing altogether, and while there are several others common to cannabis, those two are most common with ID grows... more on that in a bit...

Trust in me when I say don't grind over the leaf overlapping thing, it's not a red flag of any kind at all... Some is normal and just fine... Personally I don't see anything to this "contact sweating " thing at all. Stomata are closed at night/dark, and there are no hydathodes (micropores) located in that area.
If you have plants that are really congested with leaves, then some judicious pruning is A-OK (which you have done already )
That's about making sure there's some good airflow through the canopy, and with proper fan placement and air movement, that's no challenge to achieve...
Now if you had actual mildew issues, we'd be singing another song, but you aren't... I see no troubles so far...

have increased the air circulation, I have given the plant a heavy defoliation twice in the past week so there would be no overlapping leaves, and this is still happening.

Again, I'm asking how heavily you are watering? Really soaked pots = more pressure on the roots to pump it out, and you also risk root rot, so tell me more about the moisture levels in the pots...
Naturally, with heavy defol's, you have taken away more surface area for transpiration and even guttation, so that could account for some of what you're seeing...

I feed this plant when I wake up, and again a couple hours before lights out (she's a heavy drinker). There's always a couple drops on the leaves at the least.

This might be part of it, and what I was asking about in your water/feed schedule. During lights out, transpiration slows way down because the rest of the photosynthesis machine is shut down,.. stomata closed, no CO2 fixing, all that jazz,... Meantime that late watering is putting added root pressure going up and out, even w/o the drawing effect of transpiration happening... Xylem is nearly all dead tissue, wicking/capillary action is how water and mineral nutes are being moved upwards... So the physics of capillary action don't take a break because the rest of the live cells are on one-

Different plants, different reactions and behaviors, expect no universal anything when it come to this! Some will be fine in conditions others may be bitchy about...

Mildew, molds, these can be strongly prevented by certain products. Some are OK in bloom, other not so much... Any foliars during bloom need to be done carefully if necessary. But for fan leaves, getting started early before bloom can help significantly... Neem (veg only, it's oily and stanky), various products made from botanical oils, Potassiun carbonate, and my favorite, biological agents can make the leaf surfaces inhospitable (but not bullet proof!) to pathogenic infections.
The latter though isn't as readily available to the public.. Actinovate might still be out there, might be others which I've not really dug around for... The one we tested here at AFN is Phyter/RotBlock (check their section). This product kicked butt in testing, really was put to task with some growers and all of them reported major improvement in fighting off mold/mildew...
Last I checked the owner wanted to see about making it readily available to the growing public. It's already used in a wide variety of Ag' crops, some cannabis too...

Anyway, for a new grower you're doing great! ... don't sweat the leaf thing anymore, it's not a problem now, and if you avoid those later waterings, you'll likely see less to no more mystery water spots...