What's a good temp and humidity to keep my room at for flowering stage?

[Delps8]

Finally purchased a portable AC for my 4 x 8 grow tent should be here next week at some point What is a good temp to keep the tent at for the flowering stage? Also, what is a good RH level? The plants are in early flowering stage... Usually I check a VPD chart for a good temp and RH value; however I read somewhere high RH can cause bud rot.

From what little I've read about it, VPD appears to be based on science (not "science™"). What I read was valid enough that I dropped the coin for a PulseGrow and I used that religiously for my two grows last year. VPD deals with transpiration not to maximize photosynthesis, though.

The source that I rely on for temperature is the research by Chandra at U Miss. The graphic that I've attached shows how photosynthesis changes as LST and PPFD change.

I've read that "high" RH can cause bud rot but never seen a description of what "high" is. My practice is to follow VPD with the emphasis on keeping temps high, use fans to keep air moving above the canopy and under the canopy, and remove vegetation that blocks air flow.

 

[Delps8]

Every time I see picture's of your plants, I dont know if I should worship you or hate you

Agreed. It's sorta like this video.

 

[Drownomatic]

@Delps8 Great chart! It looks like 30/1500 is a sweet spot to be

I try to go by this chart.

But as others noted, it varies by strain.

I have about 15F drop at night. I believe this helps making colors.

 

[Delps8]

@Delps8 Great chart! It looks like 30/1500 is a sweet spot to be

I try to go by this chart.

But as others noted, it varies by strain.

I have about 15F drop at night. I believe this helps making colors.

View attachment 1425260

That's a great chart. The spreadsheet that Pulse did is more detailed but this covers all of the growth phases and there's no need to run Excel. You can just print it out and put it up on the wall. Good find.

 

[MassMom]

My house REALLY suffers from low humidity.
In the baby/veg tent I put a pan of water on top of a seedling heat mat to keep humidity about 70% from germ to
about 1.5 weeks. Then I turn off the heat mat and humidity drops to 50%. I dont even bother in the big flowering tent and it hangs around 35%. I do use little 60% humidity packs once the bud is jarred up...

XOXO
Mom