T5's a few inches from canopy? BUD TEMPS 90+!
- Thread starter joehartley
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TassieConvict
Active Member
I had this exact problem when i grew in an old water tank with a 250w hps... summer daytime temps would sometimes get over 35deg celcius and i had no way to control the temp out there, I ended up running extra darkness one day to switch them to a 9pm - 9am lights on cycle, i got no herming etc from doing this (i cant promise the same results for all though so do it at your own risk) and then it allowed me to not cook my plants during the day lol. Also helped in winter when night time temps got down close to 0 deg celcius.
Failing that, to me, light intensity comes 2nd to controlling temps so id personally just move the light far enough away to control the temp rather than worrying about how many inches away it is
joehartley
Member
As mentioned, I gradually adjusted light schedule from day to night (from 7am-7pm to 10pm-10am) and apparently the lights being off during the daylight, even though I 95% light-proofed my grow room which is inside a shed that is about 90% light-proofed, my plants apear to have gone back into veg state from a very dim light leak. I also have Nitrogen toxicity, I assume from soil used since I always used less nutes than recommended. I flushed and they appear to he doing better, except for bud production at a standstill. Not sure if theexcess Nitrogen caused them to stretch and stop flowering or the dim light leak. That is, all except one plant that's in a pot shared with one other plant. They are all from the same bagseed. Wierd.First grow is a learning process for sure.
On a positive note, I received my shipment of 5 different autoflowering strains/hybrids! Germination in process
On a positive note, I received my shipment of 5 different autoflowering strains/hybrids! Germination in process
CRN
Member
I'm using a Sun Blaze 22 T5 system covering 1/2 of the plant supplemented with a couple CFL's for the other 1/2, my Avatar shown is that plant. I keep my plant 3 - 3 1/2 inches from the T5 bulbs, and about the same on the CFL side. I've been rotating the plant on a regular basis so it gets equal treatment light-wise, which will end shortly as I just flipped it to flower and wont be able to rotate it once it reaches the screen. My plant is growing in a small alcove downstairs open to the basement that is 68 degrees. I just don't understand how you can be generating that much heat from the T5's. Maybe you could check on Craigs List or similar for a small room a/c.
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joehartley
Member
You're in a 68° basement, I'm in a 88° (today's current temp) outbuilding. T5s (8 - 4 ft 54w bulbs) are 10" away andtop of canopy is 92° with 2 fans blowing away. Can't run A/C in this building due to wiring and poor insulation/metal roof. Just have to make do on this first grow and hope for the best.
I'm working on a plan for my new autoflowers that are currently germinating. Moving grow room to a low-to-the-ground, insulated, concrete block pump house.
Heartolearn
Member
My ambient temp in my grow space is around 85 degrees during the day and 70 at night. I have 50 to 70 degree air from an air conditioning going in at all times with a fan mixing the cold and hot air. Seems to keep my canopy around 84 with about 4 to 5 inches away. I also have a small 4 inch desk fan blowing on my bulbs to try and move the heat any from plant. I am running a 2 ft 16 bulb t5 set up 50/50 veg/flower bulb ratio . I know you can not condition the space you are in but a small 5000 btu 110v a/c could help keep your growing space cool if you have no other options. Some strains can handle higher Temps better than others. Day 15 from the 12/12 switch.
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joehartley
Member
At 84 ambient temp, I can keep my canopy at 82 with lights 7" away and one fan blowing on plants thru open grow room door. Really can't justify an A/C for no temp reduction.
The whole deal is being able to get lights closer than 5" or 6" so the puppies will grow like crazy and not stretch.
4 weeks in flower, nitrogen toxicity! GRRRRR
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Heartolearn
Member
Yes the big one is a sativa plant. Silver lemon haze. The one in the back is an indica. More bushy. Both have been topped. The sativa was topped and then each main branch was topped an additional time. They are a total of 2 and half feet in length. I also have this one vegging under 4 23w cfls and 3 5w led lights. It is kept in 75 degrees and 24 hour light. No stretch as of yet.
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Heartolearn
Member
Sorry the ambient air in the actaul 35inch by 35 inch by 6 feet area is around 78 79 but with out the little bit of a/c I have running to the grow space it would exceed 95 degrees. My lights currently are around 3 inches from closes top. With lots of bud growth on tops of canopy pretty close together. Also my first grow. Started out with 8 23w cfls and adjusted lights twice a day to keep from burning leaves which is why I moved to t5. Just a suggestion to keep Temps down and if you have a 110 outlet on your light you could piggyback the a/c off of it.
joehartley
Member
So you're running off the a/c vent diverting some to your grow space? Is that then your source to force out hot air from your lights? Instead of an inline fan?
Heartolearn
Member
I have a small fan 4 inch walmart desk fan blowing up at the lights self to blow off any heat and a 12 inch room fan mixing the hot air with the a/c so I don't just blow 50 degree air on my plants. I am able to keep canopy Temps low enough to put my plants 2 to 3 inches from the tops.
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roachfinder
Well-Known Member
What's the highest temp you think u can run with led???
HansBud
Well-Known Member
I'm not sure what you mean but the highest my temps have gotten is about 81f before that it would get to the high 90s
roachfinder
Well-Known Member
Ok..my temps are in the high 90's and the low is about 85-86. I have an led light that doesn't generate much heat. I am trying to get info from multiple sources to see how "Mary" reacted in high temps. It has gotten 102-106 f. Ambiant r.t. a couple times.
HansBud
Well-Known Member
ahhh I see, from my experience anytime my tent was over 90f my plants just didn't look happy they were droopy and almost wilted looking. But that also depends on strain and genetics some strains love the heat!! Some do not
roachfinder
Well-Known Member
well I'm not.sure of the strain. It looks like a hybrid....and taking the heat well
Mrjacob274
Active Member
Mine have never seen over 86. Not even my tallest one. I just have one standing fan on low and run my lights from 9pm-9am.
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joehartley
Member
View attachment 3724108 View attachment 3724107
Mine got over 105° for a couple hours one time. As I've refined my inlet and exhaust ducting my average bud temps dropped from 96° down to 86° and daytime ambient "feels like" temps have been high 90s in my area. I have eight 4 foot T5s 4 inches above tallest buds, 6 inches above most of the canopy.
I'm sure high heat is not good for them. But my main issue has been nitrogen toxicity (at 5 weeks flower). Stunted bud growth something fierce.
And produced nanners on this clone that WAS looking pretty darn good.
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roachfinder
Well-Known Member
Well I'm just worried that the heat will cause enough stress to turn my girls to hermys. I havnt switched to 12/12 yet. so hopefully I'm golden....I got air coming in from out side now so the highest temp I get now is about 90. Thanks for your input.View attachment 3724112 View attachment 3724108 View attachment 3724107
Mine got over 105° for a couple hours one time. As I've refined my inlet and exhaust ducting my average bud temps dropped from 96° down to 86° and daytime ambient "feels like" temps have been high 90s in my area. I have eight 4 foot T5s 4 inches above tallest buds, 6 inches above most of the canopy.
I'm sure high heat is not good for them. But my main issue has been nitrogen toxicity (at 5 weeks flower). Stunted bud growth something fierce.
And produced nanners on this clone that WAS looking pretty darn good.
View attachment 3724106
View attachment 3724112