Temperature Poll (VOTE ON THIS POLL!!)

Whats your temperature with lights on?

  • 70-75

    Votes: 3 11.1%
  • 75-80

    Votes: 15 55.6%
  • 85-90

    Votes: 9 33.3%
  • 95-100

    Votes: 0 0.0%
  • 105+

    Votes: 0 0.0%

  • Total voters
    27

community

Active Member
What are your average temperatures when your lights are on?

Obviously everyone wants 70-75, but many people are growing in tight and poorly vented spaces. What do you consider safe temp? How hot is too hot?
 

uhprentis

Active Member
I've been kinda lucky as I don't have great ventilation 'yet' (working on it) because of the time of year/weather. That's beginning to change and last week we had a few unseasonably warm days, around 65F at night, where the temps hovered around 82-84. That's changed for now and I figure I have time to finish harvest (One plant in the 4th week of flower ATM) before I start to have more serious trouble as we get into Spring and things warm up.

I'm new to growing but I am a fast study and I've done a fairly good job educating myself thusfar I think. I've only seen problems up in the mid eighties when the light is within a certain range. I've got a 400W HPS on her so if I am say within 10-16 inches and the temps rise above 80 for too long that seems to be the limit for the leaves which I've seen then burn or simply curl overnight on the tips and edges. Raising the light helps that some, but the plant still slows down a lot after a while of that, combined with the loss of Lumens increasing exponentially with the distance it just hurts all around.

So anyhow, what I've gathered is the general consensus is that if one were to absolutely have to pin down a 'best temp', most seem to say 78F.
That said, I also understand there to be an 'exception' of sorts to that, where higher temperatures can be preferable, up to as much as 85F in fact, however 'only' with the addition of CO2 levels well above the nomal levels expected. Normal levels being 300-400 PPM and the elevated levels being in excess of 1200 PPM, or 'at least' 3 to 4 times higher. Levels of CO2 at or beyond 2000 PPM, however, are generally considered the 'burn' point for plants.

REF: http://tinyurl.com/cuqcga

I'll bet this is old hat to 90-95% of those here from the knowledge I've seen around these parts, so sorry for the history lesson for all the old hat guys.
 

uhprentis

Active Member
80-85F is not listed...
Doh, nevermind I misunderstood, tht you talking about my post lol.

Nothing to see here, move along

----------------------------------------

Hey :-)

It's really other references for the low end of 80F but check bottom of page 187 for this which gives the general idea:

"CO2 enriched Marijuana demands a higer level of maintenance than normal plants. Carbon Dioxide enriched plants use nutrients, water, and space up to twice as fast as un-enriched plants. A higher temprature, 85 degrees F, will help stimulate even more rapid metabolism within the super enriched plants."
 
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