Temp vs humidity to get VPD in range??

nsw3913t · Oct 4, 2022

So according to what i have seen, doing some research, the ideal flower temp for day is around 75f and RH is around 40% and any where from 1.0 to 1.5 kpa for vpd is ideal for flower. I have found that i can get around 74f and 50 RH and get about a 1.4 kpa. Now if i raise temp and lower RH the kpa goes towards the 2.0 point. How can you get your temp correct with a low RH and still keep the kpa around 1.3ish. And is it really necessary to do this. Which numbers are the important ones? I am too late in flower to fix what i have but next run i will be using bigger pots and less plants for my tent. I also have a huge jump in RH when i water, as would be expected, but i cant get it down to 40. I have a large dehumidifier for the lung room and exhasut my tent outside. Just want more control. TIA for any advice! Pics are at 38 days since flip. And of a few diff strains, same tent. Had some set backs. Thanks again.

ninjadip · Oct 4, 2022

"Just want more control."
Easiest way is to get stronger exhaust that is on a variable controller linked to humidity. With the extra power comes more control, because you can lower it and have this reserve when you need it.

nsw3913t · Oct 4, 2022

ninjadip said:
"Just want more control."
Easiest way is to get stronger exhaust that is on a variable controller linked to humidity. With the extra power comes more control, because you can lower it and have this reserve when you need it.

Yeah i have a 60x60x80 tent w one 6inch ac infinity inline and it almost has to be on max most of the time. Wud an 8inch solve the problem? Have a 6in for intake also and 800w leds w recirce fans that oscillate. The lung room runs about 34% rh and 70f all the time.

nsw3913t · Oct 4, 2022

nsw3913t said:
Yeah i have a 60x60x80 tent w one 6inch ac infinity inline and it almost has to be on max most of the time. Wud an 8inch solve the problem? Have a 6in for intake also and 800w leds w recirce fans that oscillate. The lung room runs about 34% rh and 70f all the time.

Oh and my tent also seems to suck itself in all the time as is lol. Cant just open botton vents since the room is used for other stuff also. Well guess i just answered some of the issue. Need a dedicated room too huh?!?!

Aqua Man · Oct 4, 2022

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 · Oct 4, 2022

Thats a potassium deficiency among others… what media are you in? Its likely an uptake issue like salinity or watering practices

nsw3913t · Oct 4, 2022

Yeah for a while i was using softened water. Didnt realize till i had to fill softner then i felt like a dumd ass.. did a 2 week purified water session and still using purified but started back w the nutrients. Now im just trying to make it to the end so i can start over lol. Using a soil and perlite mix but gunna change that next time also. To a coco mix, havent decided which one yet. Plus i was under watering too, lots of mistakes.... first grow since 30 yrs ago when i just did what ever lol. Any suggestions to help salvage what i got is greatly appreciated! Pls ask any questions and ill let you know what i have going on. Thanks a lot!! Oh i was doing 640ml a day in 3 gal pots do to massive run off i didnt use more water. Now i have trays under the fabric pots and last water was 4 liters w nutes and it finally saturated the soil, per another person on this forums suggestion, and im 3 days into that and soil is still wet or norm using hygrometer.

Temp vs humidity to get VPD in range??

Temp vs humidity to get VPD in range??

nsw3913t

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