Optimal rH level ?

[Dizzy88]

Just throwing a shot out there hoping some of the experts can help with my first grow.

am growing 2 plants in 5 gallon DWC... pretty simple set up In a 4x4 grow tent that I got in my garage

Garage is uninsulated — Temps/rH in grow tent basically mimic outdoor temps Plus or minus 3-4 degrees. When lights on/off

- have an ac infinity t-6 Inline fan exhausting 24/7 at 3 speed setting connected to charcoal filter (is this wrong to do?? )

- one of the bottom vent holes of tent slightly open for air intake.

- one mini fan blowing 24/7 slightly over the plants (Under the light ) and one oscillating fan thruout tent running light setting 24/7 .

- lights are on 18/6 and I have them cycled off from 3-9pm which is hottest part of our days because temps get 85-90 with lights on during warmest days. My humidity usually at 50-65 without any humidifier running with lights on... but I reckon at night It mimics the 70-80 outdoors.

my question is twofold

what is the optimal rH level I should be aiming to be at ? All sites have given various answers. During day here we usually at 45-60 humidity but at night we are at 70-90. Should I be running a mini dehumidifier throughout the night ?

are the sky high 85-90 temps with lights on going to hurt my plants ? Really can’t afford to run a Ac unit in the garage at the moment as still working on insulating it in near future.
Any alternatives to lowing temps in grow tent itself or will The two fans suffice ?

any help greatly appreciated

keep Tokin n learning

 

[Aqua Man]

Just throwing a shot out there hoping some of the experts can help with my first grow.

am growing 2 plants in 5 gallon DWC... pretty simple set up In a 4x4 grow tent that I got in my garage

Garage is uninsulated — Temps/rH in grow tent basically mimic outdoor temps Plus or minus 3-4 degrees. When lights on/off

- have an ac infinity t-6 Online fan exhausting 24/7 at 3 speed setting connected to charcoal filter (is this wrong to do?? )

- one of the bottom vent holes of tent slightly open for air intake.

- one mini fan blowing 24/7 slightly over the plants (Under the light ) and one oscillating fan thruout tent running light setting 24/7 .

- lights are on 18/6 and I have them cycled off from 3-9pm which is hottest part of our days because temps get 85-90 with lights on during warmest days. My humidity usually at 50-65 without any humidifier running with lights on... but I reckon at night It mimics the 70-80 outdoors.

my question is twofold

what is the optimal rH level I should be aiming to be at ? All sites have given various answers. During day here we usually at 45-60 humidity but at night we are at 70-90. Should I be running a mini dehumidifier throughout the night ?

are the sky high 85-90 temps with lights on going to hurt my plants ? Really can’t afford to run a Ac unit in the garage at the moment as still working on insulating it in near future.
Any alternatives to lowing temps in grow tent itself or will The two fans suffice ?

any help greatly appreciated

keep Tokin n learning

This should explain it for ya. It changes throughout the grow and based on each individual grow.

Yes general guidelines will work. But this way you understand it.

VPD (vapor pressure deficit)

Ok i was gonna sit down and write out a whole article but i have been lazy so instead instead I'm going to copy paste because im lazy. This is not my work so let start. You may find this very long but its worth the read. Some may want to skip ahead. I have added here and there to what i feel is...

www.thcfarmer.com

 

[Dizzy88]

Going to read that right now brotha ! Rolling one up and going to ingest that knowledge

 

[Dizzy88]

This should explain it for ya. It changes throughout the grow and based on each individual grow.

Yes general guidelines will work. But this way you understand it.

VPD (vapor pressure deficit)

Ok i was gonna sit down and write out a whole article but i have been lazy so instead instead I'm going to copy paste because im lazy. This is not my work so let start. You may find this very long but its worth the read. Some may want to skip ahead. I have added here and there to what i feel is...

www.thcfarmer.com

@Aqua Man ... very interesting read aqua thanks for spreading that knowledge. I am horrible at math/excel but will have to find a way to figure out that formula also need to invest in a temp gun this week for leaf temps !!

it says veg we need to aim for 0.8-1.1vpd ... for a dummy like me could u possibly tell me what rH and temp level achieves that range ???

 

[AnselAdams]

@Aqua Man ... very interesting read aqua thanks for spreading that knowledge. I am horrible at math/excel but will have to find a way to figure out that formula also need to invest in a temp gun this week for leaf temps !!

it says veg we need to aim for 0.8-1.1vpd ... for a dummy like me could u possibly tell me what rH and temp level achieves that range ???

 

[Aqua Man]

If you can give me a air and leaf temp I can give you the RH. Will check back after. Off for a nap

Just found a Free app here.

VPD Calculator - Vapor Pressur - Apps on Google Play

Simple calculator to generate VPD based on Air/Surface Temps and Humidity.

play.google.com

 

[Aqua Man]

Only thing is that doesn't take leaf temps into account

 

[AnselAdams]

@Aqua Man ... very interesting read aqua thanks for spreading that knowledge. I am horrible at math/excel but will have to find a way to figure out that formula also need to invest in a temp gun this week for leaf temps !!

it says veg we need to aim for 0.8-1.1vpd ... for a dummy like me could u possibly tell me what rH and temp level achieves that range ???

You may want to get one of these ==> https://pulsegrow.com/products/pulse-one

I have four and will be buying at least two more.

Happy Growing

 

[Dizzy88]

Only thing is that doesn't take leaf temps into account

wow... not going to lie i've spent countless hours reading/studying trying to formulate plans for perfect grow room conditions/rez conditions and all that jazz (not to say its not important) but never really tuned in to the importance of LST (leaf surface temp)... yet that is arguably one of the most crucial aspects!!!

@AnselAdams leaf temp side... if my grow room is running 80-90f during the day with lights on... i need to boost my grow tent rH up to 75-80 to achieve my needed VPD of 0.8-1.1??? and here i am trying to get it down to 50-55 LOL

 

[AnselAdams]

wow... not going to lie i've spent countless hours reading/studying trying to formulate plans for perfect grow room conditions/rez conditions and all that jazz (not to say its not important) but never really tuned in to the importance of LST (leaf surface temp)... yet that is arguably one of the most crucial aspects!!!

@AnselAdams leaf temp side... if my grow room is running 80-90f during the day with lights on... i need to boost my grow tent rH up to 75-80 to achieve my needed VPD of 0.8-1.1??? and here i am trying to get it down to 50-55 LOL

That is why we are here. Enjoy.

Happy Growing

 

[Dizzy88]

That is why we are here. Enjoy.

Happy Growing

alot of the members on this site have been very helpful to me thus far , really appreciate it - especially Aqua... big respects to him! i am hoping to get my grow room (garage) insulated and drywalled by the winter so i can better control the ambient room temp and conditions, but until then i just got the 4x4 tent sitting in there and learning as i "grow" lol.... the conditions in garage aren't the worst...but they basically mimic the outdoor temp (more of a shed so to speak in current condition) but eventually hope to get a window or portable ac unit and connect that to the tent somehow for cool air exchange (or even a DIY "CRAC" system lol... don't wanna get too far ahead of myself though thats just from my reads on here LOL)

at the moment i'm going to order this infrared gun and hope to get to get it next 2-3 days off AMAZON so i can start capturing LST and measuring my ideal VPD target to be at. i LOVE that PULSE machine... definitely will be a investment for me once i get situated more with the grow area and eventually into a RDWC system.

is there a ideal LEAF SURFACE TEMP we should aim to be at? i was reading between 72-82 online just now...

 

[AnselAdams]

alot of the members on this site have been very helpful to me thus far , really appreciate it - especially Aqua... big respects to him! i am hoping to get my grow room (garage) insulated and drywalled by the winter so i can better control the ambient room temp and conditions, but until then i just got the 4x4 tent sitting in there and learning as i "grow" lol.... the conditions in garage aren't the worst...but they basically mimic the outdoor temp (more of a shed so to speak in current condition) but eventually hope to get a window or portable ac unit and connect that to the tent somehow for cool air exchange (or even a DIY "CRAC" system lol... don't wanna get too far ahead of myself though thats just from my reads on here LOL)

at the moment i'm going to order this infrared gun and hope to get to get it next 2-3 days off AMAZON so i can start capturing LST and measuring my ideal VPD target to be at. i LOVE that PULSE machine... definitely will be a investment for me once i get situated more with the grow area and eventually into a RDWC system.

is there a ideal LEAF SURFACE TEMP we should aim to be at? i was reading between 72-82 online just now...

From what I have read; that seems like a good place to start.

 

[Aqua Man]

Just a tip on VPD it really it

alot of the members on this site have been very helpful to me thus far , really appreciate it - especially Aqua... big respects to him! i am hoping to get my grow room (garage) insulated and drywalled by the winter so i can better control the ambient room temp and conditions, but until then i just got the 4x4 tent sitting in there and learning as i "grow" lol.... the conditions in garage aren't the worst...but they basically mimic the outdoor temp (more of a shed so to speak in current condition) but eventually hope to get a window or portable ac unit and connect that to the tent somehow for cool air exchange (or even a DIY "CRAC" system lol... don't wanna get too far ahead of myself though thats just from my reads on here LOL)

at the moment i'm going to order this infrared gun and hope to get to get it next 2-3 days off AMAZON so i can start capturing LST and measuring my ideal VPD target to be at. i LOVE that PULSE machine... definitely will be a investment for me once i get situated more with the grow area and eventually into a RDWC system.

is there a ideal LEAF SURFACE TEMP we should aim to be at? i was reading between 72-82 online just now...

Without CO2 75-77 for most ideal photosynthesis. Mine are at about 80-81 but I run 1200ppm co2

 

[Dizzy88]

Just a tip on VPD it really it
Without CO2 75-77 for most ideal photosynthesis. Mine are at about 80-81 but I run 1200ppm co2

LOL just dug up the ol cabinet and found the infrared thermometer used to read for fevers n all that ... LST on the plants was showing 34.1-34.3 celcius across the board which is 93 farenheight. and that is with lights off.... im way too high if we need to be at 75-77. My LED is 24 inches above the plants, should i back it up?

current conditions - 82F temp... 60 rH ... 93 LST ...

 

[AnselAdams]

LOL just dug up the ol cabinet and found the infrared thermometer used to read for fevers n all that ... LST on the plants was showing 34.1-34.3 celcius across the board which is 93 farenheight. and that is with lights off.... im way too high if we need to be at 75-77. My LED is 24 inches above the plants, should i back it up?

current conditions - 82F temp... 60 rH ... 93 LST ...

SSSSSSSSCCCCCCCOOOOOOOOORRRRRRREEEEEE!!!! ☠ aren't treasure hunts fun?

 

[Aqua Man]

LOL just dug up the ol cabinet and found the infrared thermometer used to read for fevers n all that ... LST on the plants was showing 34.1-34.3 celcius across the board which is 93 farenheight. and that is with lights off.... im way too high if we need to be at 75-77. My LED is 24 inches above the plants, should i back it up?

current conditions - 82F temp... 60 rH ... 93 LST ...

What kinda lighting are you using? I can't see that temp being accurate.

 

[Dizzy88]

i have a 1000W MARS HYDRO LED

 

[Aqua Man]

i have a 1000W MARS HYDRO LED

Yeah that's not right... You sure it set to read surface temperature and not body temperature?

Also the IR gun should usually be anywhere from 8-14" away from the leafsI don't know what yours requires.

 

[Dizzy88]

Yeah that's not right... You sure it set to read surface temperature and not body temperature?

Also the IR gun should usually be anywhere from 8-14" away from the leafsI don't know what yours requires.

probably is set ready to read body temp... durrr another dummy moment of mine lol.... well i'm going to order that one off AMAZON for sure then - i seen one on at home depot, i am going to see if that one reads surface temp if it does i might just go scoop that now.

 

[Dizzy88]

probably is set ready to read body temp... durrr another dummy moment of mine lol.... well i'm going to order that one off AMAZON for sure then - i seen one on at home depot, i am going to see if that one reads surface temp if it does i might just go scoop that now.

@Aqua Man @AnselAdams ... off to home DEPOT... LOL the one i had was body temp, going to get this IR gun from home depot now.