Hey, we have some Afghans flowering in our closet; in soil. In arizona, temps are high and humidity is low. In our closet with the flowering Afghans, during "daylight" hours, temperature averages around 89-91F, and humidity fluxuates between around 25%-35%. ( we have a fan set to go on/off with the light, set to medium-low speed; and I have placed a tub of water under the light with the intent of aiding in humidity; plus we have one of those co2-generating bags in front of the fan ) I'm wondering, are those temps and humid. extreme enough to cause problems with our plants? I read that flowering temps should be best at approx. 85% and flowering humidity should be less than 50%. Also, what sort of temps should I really start worrying at? 95F... 100F...? And what about humidity... 20%....15%? In other words, what are the definite 'red' zones? One other question, not really related: how far from the tips of my flowering plants should a 400W HID be located to prevent burnt top colas?
[quote name='"exponent"']Hey, we have some Afghans flowering in our closet; in soil. In arizona, temps are high and humidity is low. In our closet with the flowering Afghans, during "daylight" hours, temperature averages around 89-91F, and humidity fluxuates between around 25%-35%. ( we have a fan set to go on/off with the light, set to medium-low speed; and I have placed a tub of water under the light with the intent of aiding in humidity; plus we have one of those co2-generating bags in front of the fan ) I'm wondering, are those temps and humid. extreme enough to cause problems with our plants? I read that flowering temps should be best at approx. 85% and flowering humidity should be less than 50%. Also, what sort of temps should I really start worrying at? 95F... 100F...? And what about humidity... 20%....15%? In other words, what are the definite 'red' zones? One other question, not really related: how far from the tips of my flowering plants should a 400W HID be located to prevent burnt top colas?[/quote] 76 degrees is optimal temperature, 20% humidity is good. during flower, humidity should be at its lowest. 95 degrees and 100 may easily kill plants, depending on strain andd phenotype. When u hang the light, ang as close yp plants while put your hand above the top cola to make sure you feel no heat, and try and put a fan between light and colas. With those temps I recommend the "on" part of he cycle to be at night, while temps are lower
Yeah, in the summer I do the light cycle at night to make sure they don't get too hot while I'm sleeping. You may want to do the same. I don't think mid 80's will hurt your plants, but it is getting there. I know on my first grow I was staying constant in the 90's and that plant was toast. Try to keep good circulation, blow the hot air away from the plants if possible.
When you get over 85 Cannabis growth stops....95-100 wont kill it really just wont get any fast growth. Cannabis can grow in hot conditions outside but it has all year to grow so it makes up for it. Indoor growing you want it below 85. Humidity is hard to control inside and of many things its on the lower end of the totem pole in terms of worry.
Hey thanks for all the helpful comments and advice, very useful and appreciated! In particular, the night-hours oriented photocycle is something I hadn't considered; that's a good idea.
Ok, so temps over 85F slows growth, and temps hitting consistent 91+F are potentially considered doomed? ( what about root temperature vs. external temperature? I've been talking in terms of external/ambient temperature, and have not yet actually monitored the soil temperature ) What's 'worse' for yield? Too-low lumens, or too-high ambient temperature? The current closet is in a constant battle between these four issues: lack of sufficient fresh air exchange vs. light seepage vs. high temperature vs. insufficient humidity Cool, that's good to know! ( juggling a variety of issues, it's good to know priorities ) So, is it basically true that there's realistically/effectively no such thing as "too low humidity" during later flowering? So heavy fan use in a closet is not problematic? ( I was thinking I ought to reduce some of the wind that was blowing in the closet, because