"Mystery" temperature rise, what am I missing here? 🤔

[Grownsince95]

Well after three days of doing it ...it stopped. ‍♂

Idk. I guess its not a big deal. And obviously not an interesting topic. Thanks to those who took the time to respond. And again, @TripsRabbit I'm sorry again I made a snippy comment at you, I quickly realized my mistake and deleted it as fast as I could. Not trying to hide my bad behavior. I respect your opinions and appreciate you chiming in.

❤❤

 

[CF89]

Where did I say “Saying that plant's leaves are not releasing moistre into the atmosphere around them”??

 

[Grownsince95]

A common misunderstanding is that the transpiration of plants will affect the humidity in a grow room

My mistake if I took that the wrong way @CF89
You didn't actually say that

 

[CF89]

All good.

one quick question though.

Let’s just say the grow room did hit 100% humidity. At that point, technically wouldn’t plant transpiration fully stop?

 

[Grownsince95]

All good.

one quick question though.

Let’s just say the grow room did hit 100% humidity. At that point, technically wouldn’t plant transpiration fully stop?

Absolutely. I think it pretty much crawls to A stop after 90%. That's why we keep clones in that environment so their leaves won't have to do any "work" they can actually get moisture from the air when they have no roots.

 

[MIMedGrower]

Plants dont follow the vpd chart. They adjust to environmental conditions. Many tests on humidity and cannabis and yield is unaffected by humidity. Its even in ed rosenthals book. Cannabis grows well in the mountains of colorado and the coast of oregon for example.

and 100% of the water given to the plants eventually transpires or evaporates into the air.

 

[MIMedGrower]

All good.

one quick question though.

Let’s just say the grow room did hit 100% humidity. At that point, technically wouldn’t plant transpiration fully stop?

No there are 20’ tall weed plants in a rain forest.

 

[CF89]

I feel like there are way too many variables to even prove it wrong one way or another.

even if you grew two identical setups, but one following the vpd chart and one with a very high or low humidity the whole time... would it even be a noticeable difference or are we talking in the 1-3% range here?

I followed it during veg a little because if I don’t, my OCD eats me up and FOMO kicks in and I’ll always wonder if it woulda been better if i had done this or that. I don’t know if I followed it properly though as I used a cheap humidity meter and didn’t read leaf temp

 

[amekins]

I don't think so, I could be wrong. The dehumidifier is definitely adding heat, but why an extra three degrees? It's a really small vivosun peltier process model, and it couldn't suck a raindrop out of a thunderstorm if it wanted to. It's basically there for emergencies. The only difference in anything that's going on when the temp rises are that the three 75 watt lights in the other tents turn off. Power issue? idk

So thinking that your other tent is getting some kind of power surge to the light that is on in the flowering tent? Is the tent position in the room closer to any heat output in the king room? How does airflow change within the room?

Updated to add: I never even saw this thread until this morning. Temps are up today here. Did you have a cold spell, heat came on in the room or even ambient temp rises, and then went off again?

 

[MIMedGrower]

I feel like there are way too many variables to even prove it wrong one way or another.

even if you grew two identical setups, but one following the vpd chart and one with a very high or low humidity the whole time... would it even be a noticeable difference or are we talking in the 1-3% range here?

I followed it during veg a little because if I don’t, my OCD eats me up and FOMO kicks in and I’ll always wonder if it woulda been better if i had done this or that. I don’t know if I followed it properly though as I used a cheap humidity meter and didn’t read leaf temp

Vpd charts are for greenhouse management. They are to mitigate high humidity not present a parameter that is desirable if you have control of temp and humidity.

I think its more misdirected forum bro science. Every test i saw showed no difference in quality or yield with low or high humidity. Temp is a factor for plant growth though.

but avoiding mold and mildew is more important imo and keeping things under 60% can prevent issues.

 

[Grownsince95]

Plants dont follow the vpd chart. They adjust to environmental conditions. Many tests on humidity and cannabis and yield is unaffected by humidity. Its even in ed rosenthals book. Cannabis grows well in the mountains of colorado and the coast of oregon for example.

and 100% of the water given to the plants eventually transpires or evaporates into the air.

Agree 100% ...except for the 10% of the water trapped in the plant's cells for life functions that's not transpired.

 

[MIMedGrower]

Agree 100% ...except for the 10% of the water trapped in the plant's cells for life functions that's not transpired.

I just assumed that water is continually replaced.

 

[Grownsince95]

Vpd charts are for greenhouse management. They are to mitigate high humidity not present a parameter that is desirable if you have control of temp and humidity.

I think its more misdirected forum bro science. Every test i saw showed no difference in quality or yield with low or high humidity. Temp is a factor for plant growth though.

but avoiding mold and mildew is more important imo and keeping things under 60% can prevent issues.

Again we agree! But a word on "bro science" ...
For many, many years farmers would meet at harvest time for festivals or markets or whatever and they'd bring their crops and some guy would show up with like monster zucchini or ridiculous tomatoes and all the other farmers would say "Hey Jeb, how did you grow such wonderful vegetables?" and Jeb would tell them all this cool stuff and those farmers would go back and repeat those techniques and pass it on and on and on.
Farmers figured out long before "science" that nice deep, loose soil grew long beautiful carrots. That's the original bro science. This forum is pretty much a yearlong farmers market Internet bro science festival

 

[Grownsince95]

I just assumed that water is continually replaced.

You would make a great litigator! This is very true, so I guess its not 100% out until we dry it...

 

[MIMedGrower]

Again we agree! But a word on "bro science" ...
For many, many years farmers would meet at harvest time for festivals or markets or whatever and they'd bring their crops and some guy would show up with like monster zucchini or ridiculous tomatoes and all the other farmers would say "Hey Jeb, how did you grow such wonderful vegetables?" and Jeb would tell them all this cool stuff and those farmers would go back and repeat those techniques and pass it on and on and on.
Farmers figured out long before "science" that nice deep, loose soil grew long beautiful carrots. That's the original bro science. This forum is pretty much a yearlong farmers market Internet bro science festival

all hobby forums and groups are. The guitar forums cost me even more needless money than the weed forums. ;-)

 

[MIMedGrower]

You would make a great litigator! This is very true, so I guess its not 100% out until we dry it...

my mom always thought so. ;-)

 

[Grownsince95]

all hobby forums and groups are. The guitar forums cost me even more needless money than the weed forums. ;-)

I play the bass and I started building my own from kits. Saved a lot of $ although I still have my "classics"

 

[Aqua Man]

So IME when you see something like this the first thought is ALWAYS sensor placement... is one closer to the dehumidifier exhaust etc.

Next is the air exchange rates and difference between tents. If your using something like a controller or cloudines that adjusts or kick on/off based on humidity its changing the air exchange between tents and therfore the temp also.

 

[Grownsince95]

So IME when you see something like this the first thought is ALWAYS sensor placement... is one closer to the dehumidifier exhaust etc.

Next is the air exchange rates and difference between tents. If your using something like a controller or cloudines that adjusts or kick on/off based on humidity its changing the air exchange between tents and therfore the temp also.

Yes two of three tents have T4's...very good point I bet thats exactly it! They tend to only run 100% on at night when the rh goes up. I have them both set for 82° and flower tent set for 60% rh. ❤❤

 

[Grownsince95]

So IME when you see something like this the first thought is ALWAYS sensor placement... is one closer to the dehumidifier exhaust etc.

Next is the air exchange rates and difference between tents. If your using something like a controller or cloudines that adjusts or kick on/off based on humidity its changing the air exchange between tents and therfore the temp also.

And there's the sensor. It's on the same side of the tent as the dehum but far enough I thought because that barely blows anything (its such crap) and the two other fans keep a really good breeze all the way down to the floor. Should I move the sensor? I think you figured it out though man thank you very much!!

The T4 sensor is the black wire in the canopy