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What are you running your climate at?

maize

New member
R u guys hitting plants with 1500 ppm from day 1 of flower ,New to co2 have all the sniffers controllers not sure where to set ppm levels in sealed room am in day 3 of flower
 

waltwalt

Member
I haven't actually tried 88/50 yet, but when I was running 84/60 I never had any problems with bud-rot, as things got later into flowering I dropped the RH to about 30%. I will see what's what this time around with hydro, I hear bigger yields from hydro so that's what I'm going for this time around. I found some monster genetics in bag-seed from an online dispensary that I'm going to monster-crop in a few weeks.

Maize - I've read people recommend ramping up the CO2 injection, but as long as you don't go over 1500ppm you should be fine. When I get to flowering I will be going 1500ppm day 1 along with raising the temps.

-ww
 
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Carl Carlson

I couldnt find the university study that showed maximum growth rate (tomatoes) and final yeild was 95 degrees at 1500 ppm and at 75 degrees for 400 ppm, but all the articles below suggest 90 degrees is better than ambient.

Here is the university study that shows maximum growth rate for Cannabis at 86 degrees.

The study is lacking in that co2 was supplemented only up to 750 ppm.

However some interesting data and conclusions to work with:

Photosynthetic response of Cannabis sativa L. to variations in photosynthetic photon flux densities, temperature and CO2 conditions

Suman Chandra1, Hemant Lata1, Ikhlas A. Khan1,2 and Mahmoud A. Elsohly1,3

1 National Center for Natural Product Research, School of Pharmacy, University of Mississippi, MS-38677, USA.
2 Department of Pharmacognosy, University of Mississippi, MS-38677, USA.
3 Department of Pharmaceutics, School of Pharmacy, University of Mississippi, University, MS 38677, USA.

According to our data on C. sativa, temperature optima for PN was observed at 30C. In general, temperature higher than 30C had an adverse effect on PN (Fig. 1A). At 25C, rate of photosynthesis increased with increasing PPFD, but this trend peaked with 1500 μmol m-2s-1 PPFD at 30C, and decreased at higher light intensities. Similar effect of PPFD was observed at temperatures higher than 30 C. Maximum rate of photosynthesis (PN max) was 24.60 μmol m-2s-1 at 30 C and under 1500 μmol m-2s-1 PPFD. The interaction of PPFD and temperature demonstrates that high PPFD and higher temperature together (PPFD × temperature) had an adverse effect on PN. In general, effect of PPFD (r = 87) was more prominent in regulating PN in Cannabis sativa as compared to temperature (r = 46).
 
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Carl Carlson

I work within these ranges:

18ºC-64,4F - 35%RH. Max 55%
20ºC-68F- 35-45% RH. <60%
23ºC-73 - 45-50% RH. 34-64%
26ºC-78 - 50-55% RH. 42-67%
30ºC-86F- 60% RH. 50-70%
 
Thanks Carl. Very reassuring. I just started CO2 augmentation this cycle. Daytime temps vary from 84 to 87, CO2 ppm from 900 to 1500+. (CO2 increases as temps rise, exhaust kicks in at 87-88, drops temps to 84 and CO2 to 1000. But when dehuey kicks in, temps rise without corresponding increase in CO2. So obviously, if I can let the RH sneak up to the 50-55% mark, or even a little higher, I can maintain the CO2 level at or near optimum 1500 for longer periods.)

Last crop I had some probs with bud rot at 50-60% RH, 400-500 ppm CO2, and temps averaging 67 night, 72 day. Since this is my first experience with ramped-up CO2, I was a little gun-shy.
 

Lazyman

Overkill is under-rated.
Veteran
Harm no, but towards the end of flower I like a 15*F drop at night, or more. I like a low night temp around 60*F in the last couple weeks, it tends to really bring out the purple colors and frost, in genetics that are so inclined anyway.
 
P

Pure.Dope

Harm no, but towards the end of flower I like a 15*F drop at night, or more. I like a low night temp around 60*F in the last couple weeks, it tends to really bring out the purple colors and frost, in genetics that are so inclined anyway.

Good to know. I can't really lower my day temps, they stay at 85-88f. I can however change my night temps as low as 65f.
 

maize

New member
The current run of ww 17 crystal did not like humidity of 50% or above all the leaves sagged and finnaly died of white widow would not head or let any pistils show at all ...i had to turn co2 off untill dehumidifier arrived //in turn they came back to life with normal humidity and co2 ..Ive been growing these clones all last year no probs until added co2 and humidity
 
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Carl Carlson

Harm no, but towards the end of flower I like a 15*F drop at night, or more. I like a low night temp around 60*F in the last couple weeks, it tends to really bring out the purple colors and frost, in genetics that are so inclined anyway.

I like to do this too.

ethylene treatment
 

Lazyman

Overkill is under-rated.
Veteran
Have you heard of the banana trick? place a ripe banana at the base of each plant to spread ethylene gas around, hahaha, hard to tell if it works you know, side by sides are a fuckin pain.
 
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Carl Carlson

you mean like how they ship unripened vegetables to the grocery story and than ethylene treatment is applied?

I had to look this up. haven't tried it.
 
P

Pure.Dope

never heard of the ethylene deal.

and sweet i thought i was the only one up. i actually was sleeping w/ my gf but just woke up and couldn't go back to sleep. gonna smoke some of this blue dream i just got. that's actually what put me to sleep in the first place. hopin it'll do it again.
 
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Carl Carlson

I should add that in my experience, cold temp. treatment during late bloom brings out purple colors, regardless of strain or variety.

I first read experienced it by accident. Than read about it in the crop stress handbook. And than did some further reading and learned that citrus growers in Florida utilize it. And tonight I just learned that ethylene treatments are used somewhat differently by producers and grocers on bananas and green vegetables that ripen and change color.
 

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