Temperature Issue in 3x3 Tent...

G

GreenMTNGrower

Member
Hey there everyone,
I have a issue that I am hoping to remedy here this week, but wanted to put this out there for some more experienced folks to
chime in and possibly share some info.

I am in a 3x3 tent, 7' high.
I have been lighting with a 315 Phantom CMH for this run.
With stretch plants larger colas are 12-14" from bottom of bulb.
I am in the NE, so we are slowly getting to summer temps here (88F max this week).
I am set up in my garage, no AC or temp control other than opening garage door at night to cool it down (lights on at 5PM - off at 5AM).
I have a thermometer at cola height and the wired probe (second temp reading) is hanging down to bottom of tent.
I have hit 90F at canopy height last week, but with the garage door open I can cycle in the cool air at night until I hit the bed by 12/1AM, so this leaves 1-5am with possible heat issues. When I am up and monitoring from 5PM to bed time, I can keep temps at like 82F with garage door open for the cool air to come in at night.
Last night I had 86F at canopy and bottom probe at 77F.

With this issue starting around Day #35ish of flower, although not consistent due to fluctuating NE temperatures (Friday is Day #56) I ordered a 4vs from Timber to replace the CMH to switch out upon its arrival and hopefully mitigate the high temperatures and actually get the light a bit higher off of the cola tops.

Only issues I am seeing is that one plant (Full Moon Fever) is yellowing on edges of leaves, with some tacoing and there are a couple of flowers that have ever so slightly begun to foxtail. Flowers are dense and not wispy at all.

No issues have been viewed on the other plant (Tomahawk) as flowers are also dense and is now just fading into some purple traits (per expected) coming through on leaves.

Ok, so here are my questions....
  1. Are the temps reported f-ing up the potency, smell, etc of the end result to come? I understand the higher temps may have slowed growth rate of flowers.
  2. When the Timber COB light comes in this week, can I replace the CMH that the grow has been under for the whole flower or is that risky and somehow shock the plant under a new light like this?
  3. These two plants have ran to day 77 in past grows, am I in danger of anything here with being a few weeks out from chop?

Thanks in advance to everyone who reads and responds.
Cheers
 

Attachments

2Hearts

2Hearts

Well-Known Member
Dont put a thermometer in the canopy or under the lights, it will read the heat frilom the light which isnt the air temperature.

Learn how to use a thermometer properly and get accurate readings. No one puts a thermometer in the sun they put it in the shade.
 
Ladre87

Ladre87

Well-Known Member
2Hearts said:
Dont put a thermometer in the canopy or under the lights, it will read the heat frilom the light which isnt the air temperature.

Learn how to use a thermometer properly and get accurate readings. No one puts a thermometer in the sun they put it in the shade.
Click to expand...
what? actually he needs to mesure under the lights what is the maximum temps. leafs are feelling hot to top.
 
farmingfisherman

farmingfisherman

Well-Known Member
Ladre87 said:
what? actually he needs to mesure under the lights what is the maximum temps. leafs are feelling hot to top.
Click to expand...
I'm a newbie with one grow inside and a couple outside. I used led and a 315 cmh and ran temps in the low 80's for the pots and upper canopy levels in the mid 80's. I'm pretty happy with how things ended up. As far as learning to use equipment I'd disregard anyone who can't come across without sounding like a dickhead. Good luck with the rest of the grow!
 
2Hearts

2Hearts

Well-Known Member
Ladre87 said:
what? actually he needs to mesure under the lights what is the maximum temps. leafs are feelling hot to top.
Click to expand...
No he dosent and you are advised to shield the thermometer from all light radiation.

There is a difference between light and air, a thermometer is not for reading light energy which is why it shouldnt be placed in the light.

This is not up for debate and has always been the correct way.
 
farmingfisherman

farmingfisherman

Well-Known Member
farmingfisherman said:
I'm a newbie with one grow inside and a couple outside. I used led and a 315 cmh and ran temps in the low 80's for the pots and upper canopy levels in the mid 80's. I'm pretty happy with how things ended up. As far as learning to use equipment I'd disregard anyone who can't come across without sounding like a dickhead. Good luck with the rest of the grow!
Click to expand...
How far above the canopy are you running the 315? Plants looks great!
 
Ladre87

Ladre87

Well-Known Member
2Hearts said:
No he dosent and you are advised to shield the thermometer from all light radiation.

There is a difference between light and air, a thermometer is not for reading light energy which is why it shouldnt be placed in the light.

This is not up for debate and has always been the correct way.
Click to expand...
not in the light, need to mesure top of your canopy.
 
G

GreenMTNGrower

Member
2Hearts said:
Dont put a thermometer in the canopy or under the lights, it will read the heat frilom the light which isnt the air temperature.

Learn how to use a thermometer properly and get accurate readings. No one puts a thermometer in the sun they put it in the shade.
Click to expand...
2Hearts - Thank you for your information. Please look at the attached photos of the canopy, the light (centered) and position of thermometer for reading canopy height. You can't see the wired probe that dangles down to the bottom of the pots for that reading. Please let me know what you think after viewing as to if I have it in a good spot or not. It is in the corner and not directly under the lamp/bulb.

Thanks
 

Attachments

Ladre87

Ladre87

Well-Known Member
GreenMTNGrower said:
Hey there everyone,
I have a issue that I am hoping to remedy here this week, but wanted to put this out there for some more experienced folks to
chime in and possibly share some info.

I am in a 3x3 tent, 7' high.
I have been lighting with a 315 Phantom CMH for this run.
With stretch plants larger colas are 12-14" from bottom of bulb.
I am in the NE, so we are slowly getting to summer temps here (88F max this week).
I am set up in my garage, no AC or temp control other than opening garage door at night to cool it down (lights on at 5PM - off at 5AM).
I have a thermometer at cola height and the wired probe (second temp reading) is hanging down to bottom of tent.
I have hit 90F at canopy height last week, but with the garage door open I can cycle in the cool air at night until I hit the bed by 12/1AM, so this leaves 1-5am with possible heat issues. When I am up and monitoring from 5PM to bed time, I can keep temps at like 82F with garage door open for the cool air to come in at night.
Last night I had 86F at canopy and bottom probe at 77F.

With this issue starting around Day #35ish of flower, although not consistent due to fluctuating NE temperatures (Friday is Day #56) I ordered a 4vs from Timber to replace the CMH to switch out upon its arrival and hopefully mitigate the high temperatures and actually get the light a bit higher off of the cola tops.

Only issues I am seeing is that one plant (Full Moon Fever) is yellowing on edges of leaves, with some tacoing and there are a couple of flowers that have ever so slightly begun to foxtail. Flowers are dense and not wispy at all.

No issues have been viewed on the other plant (Tomahawk) as flowers are also dense and is now just fading into some purple traits (per expected) coming through on leaves.

Ok, so here are my questions....
  1. Are the temps reported f-ing up the potency, smell, etc of the end result to come? I understand the higher temps may have slowed growth rate of flowers.
  2. When the Timber COB light comes in this week, can I replace the CMH that the grow has been under for the whole flower or is that risky and somehow shock the plant under a new light like this?
  3. These two plants have ran to day 77 in past grows, am I in danger of anything here with being a few weeks out from chop?

Thanks in advance to everyone who reads and responds.
Cheers
Click to expand...
now ıam growing indica domimant strains sometimes its going 91.4 maybe more they can handle this, canabis plands are harsh. dont worry about it you are doing good. you mentıon about foxtail thats not happened this 14inc far above the canopy. probably depent on strain.

your questions

1-yes it is all true but if you dont use ac unit you cant do anything about it. normal condintions you need to max 82.4 F.
2- in first 7 days maybe more thay will get used to your new cob light. in that moment you temps are gets lower that means its good!
3-when your plants ready you can chop it. do not delay more then a few weeks you sould be fine.

I hope its help. do what you doing nice job.
 
Last edited:
farmingfisherman

farmingfisherman

Well-Known Member
GreenMTNGrower said:
Farmerfisherman - thanks for the post. I have included a picture of the measurement from the top of the highest middle cola to the tip of the bulb. It measures 13 -14 inches for the distance between the two.

Let me know any additional thoughts.
Click to expand...
Damn that is closer than I ever got when I had my grow going. Are you rotating the plants around? Also I wonder if there is a difference between the bulb being hung horizontally vs vertically. Plants really do look great. I wonder if the uv light they are receiving would be missed if you were to replace it with the Timber. Since I used both I can't really weigh in on that subject. I have heard that the both the 315 cmh and leds can cause the plants to be on a different finishing schedule than those grown under HPS lights. So much to learn still.. I wish you cool weather for the next few weeks! :peace:
 
G

GreenMTNGrower

Member
farmingfisherman said:
Damn that is closer than I ever got when I had my grow going. Are you rotating the plants around? Also I wonder if there is a difference between the bulb being hung horizontally vs vertically. Plants really do look great. I wonder if the uv light they are receiving would be missed if you were to replace it with the Timber. Since I used both I can't really weigh in on that subject. I have heard that the both the 315 cmh and leds can cause the plants to be on a different finishing schedule than those grown under HPS lights. So much to learn still.. I wish you cool weather for the next few weeks! :peace:
Click to expand...
That's all the room, height wise, I have in the tent. The exhaust and carbon filter are seated right above the hood....the timber will give me another 4-6" of height for light and the dimmer option....supposed to get here tomorrow.
 
You must log in or register to reply here.
Top