Thought a little discussion could be in order for the highest temps you’ve run, weather it be on purpose or hard to control like myself currently Curious what the hottest is people have ran without killing the plant! I remember seeing an autoflower grower in the 100’s F my hottest temps have been 92F and currently running around 87-90F my ventilation is not set up proper and my intake is bringing in back too much heat, Haven’t seen any signs of heatstress as I;ve kicked all my oscilating fans on max aswell as I;ve introduced Co2 . One is loving it! Although I do want cooler temps for colours and denser nugs !
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I’ve seen 34C (93F) in the past during summer in the various lofts I’ve known and hated. It was a struggle to keep up with the water demand. Bud rot didn’t seem to struggle at all though, it thrives in those conditions 
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My autos are sitting at 81 at the moment with lights on. They sometime go as high as 85. I’ve not seen any Ill effects at all. The 6 hours lights off they drop to around 70. Humidity is at 40%. I don’t run c02. The air is drawn from outdoors and it’s filtered into the room the tent is in. They do require watering a bit more often but weed grows fine in a lot harsher conditions.
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My first grow of Durban, I was all new to this, and my tent was running about 95 to 97 degrees. It didn’t seem to bother my plants maybe because it was Durban.
For my second grow I constructed a vent system which keeps my tent around 80 to 85 degrees.
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How does your ventilation system works mate 
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I whipped it up out of some sdr-35 pipe that I had kicking around.
Solid pipe on the vertical and drainage pipe for the actual vent, thermostatically controlled.
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Here’s a couple more pictures, of course the floor looks cruddy but it was cleaned…
The pipe in the bottom is an intake with a filter on the outside.
The fan is plugged into a thermostatic controller and will turn on at whatever temperature I set.
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I saw 104f once in my room. They were African sativa’s so it wasn’t to bad.
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No grow room but, I’ve had plants in AZ summers at 110+ and they didn’t seem to mind as long as I kept them hydrated they were partially shaded throughout the day though
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Wow some Hot temps thats forsure!! Mine seem rather happy currently I am suprised! I have both my 6" intake and 6" exhaust both being sent out through a 6" intake/excahnge single unit, so essentially 3" and the intake is at the same hole as the exhaust… So going to seperate them now and 6" each so I’m hoping that will really save my bacon and I want to see some colours!
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My tent was hitting 90’s but they made nanners so it wasn’t good for me. Also the mites liked it and now dealing with them.
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One grow around constant 100F or so…
Never again 
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I’m trying to run a 400w hps in a 80x80x160cm tent am the temps r getting really high 35*c sometimes any ideas to get the heat down peeps cheers 
Cool tube. Air conditioner. Have your light period during the night and your lights off during the hottest part of the day. Look at changing to LED lighting.
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I’m currently using the metzhi 600w (270w from the wall) and a small 300w led (130w) but don’t seem to be getting more than a couple of oz per crop so far I’ll also be using coco this time in search for at least 6 oz per crop at least it would feel I’m getting mid range crop for my effort lol and sorry the hps would be for flower only
My Box with 4COB LED in Panel
in Box12060200cm
tt100 vents withj 187m3 +360m3 carbonfilter
And in hot summer days i had around 33-34*C
and girls was okay 
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Yeah man I no u can run them hot just how hot and for long @Krefeld I’ve got 6” 2 speed fam and carbon filter and still the temps rise:crazy_face:
as anyone done a full run with really high temps from start to finish cheers
@Stonkie yeah bro it was for all flowering phase so every day from 12:30 ( sun starts to hit the window ) till goes down … mby for 8-9 hours every day 
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I’ve got autos running this time so I am going to be having these on 18hrs a day start to finish mate and I don’t no how autos will handle the heat pal
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The meizhi 600 is a good light. I’m running one myself alongside a Yaetek 600 and a cheap Chinese 1000w blurple.
All together they pull just under 600w at the wall.
The strain you choose is a big factor on yield.
On Saturday I will be 4 weeks into my auto grow.
Devil xxl auto I’m growing are HUGE compared to the white widow auto alongside them. Devils have showed there sex and started the stretch. The widows are lagging behind. No pitils or stretch from them as yet although they are very healthy.
Devil in soil.
White widow in soil.
One of each in DWC. You can clearly see the size difference between the 2 in that picture.
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