Hi all, so this is my 2nd grow run in a 4x4x8 tent with a 530 watt led w a 6" exhaust fan and 2 oscillating fans. the tent is in a closet that is not much larger than the tent itself width wise and maybe 2 feet taller. on my first grow run the temps stayed between 74-78 during germ and through veg but once I turned the lights up to full strength for flower my temps rose b/w 80-86 and I could never bring them below this which caused some stunting and later mold problems that I have bought a dehumidifier to correct on this run as well as a co2 tank. I have been testing the setup before I get started w the lights on full strength and fans in different locations to pull and push the air but I just cant seem to bring the temps down below 83. I don't want to buy an AC unit unless I absolutely have to but I am unsure of what else to try. any tips or suggestions would be much appreciated
Temperature too hot in tent: please help
- Thread starter wilksgrow
- Start date
Your first grow, was it in the winter? Easier time controlling temperatures for indoor grows in the winter over summer. I would normally say if you create a higher volume of air flow entering the tent, as well as exiting the tent, might help, but in summer temps it’s hard to maintain those cooler temps without actually lowering the temps outside the tent. If you cant lower the temps outside the tent with opening windows and better air flow, then maybe an ac unit might be beneficial 
No Pain
Well-Known Member
well first those temps are nothing to worry about as far as mold its due to humidity and to drastic of a drop in temperature between lights on and lights off ..its best to try and keep a 5 degree difference between those times . It also sounds like you need to rethink / look at your exhaust .
now to dial in your environment you will need a couple things ..a laser thermometer to measure lst (leaf surface temperature and a gauge that reads temp and humidity at plant level .. here is a CHART for VPD vapor pressure deficit as it all has to do with transpiration of the plant ,
depending on the humidity levels it may not be in your best interest to run co2 and to exhaust 100% of the air from your tent .
HugePeckerhead
Well-Known Member
Small air conditioner? they have ones that don't need to be in a window
Keeping the tent open always works for me
But as mentioned, suck air from a cooler area, and into the ceiling would help
But 83 is fine, I've ran close to 90 and never had issues
But as mentioned, suck air from a cooler area, and into the ceiling would help
But 83 is fine, I've ran close to 90 and never had issues
Remystemple
Well-Known Member
I was having some heat up to about 85 last month. even with an ac in the room. it turns out the trick for me was to open enough of the vent holes and flaps to cancel the negative suction of the tent. as soon as the walls stopped sucking in so hard the temps went down by about 7 degrees. the walls of the tent just kind of fluttered after that.
Bush Doctor 77
Well-Known Member
My temps in the greenhouse near 100F for the last 2 weeks, and 25% humidity. I'm not seeing any stress.
Sounds like you need more airflow through the closet. What is the temp in the rest of the house? The temp in the closet?
During the summer months my flowering tent temps range from 78-86F during flower. I've found that the higher temps during flower seems to help with nitrogen cycling and nutrient availability which I assume is due to the increased microbial activity as a result of the higher soil temperature. The higher temps also seem to cause the plants to produce higher concentration of trichomes as a defense mechanism.
That being said, I suspect that the higher temps may also be slightly diminishing the terpenes somewhat as higher temps are know to flash off volitile esthers and flavinoids and whatnot.
As others have mentioned, the PM or bud rot issues that you are experiencing would likely be due to high humidity conditions which you'll need to address.
One tip that doesn't cost any money and can be implemented right away is to always water your plants during the early part of the lights on period and DO NOT water within 4 to 6 hours of lights off.
Humidity levels inside of your tent will always increase once your lights go off. But if you water just before lights off it will cause an excessive increase in humidity levels compared to if the medium were left unsaturated with water overnight. Oh, and do make sure that you keep both your air circulation fans and tent air extraction fan(s) on during lights out to ensure good air circulation and continual fresh air replenishment.
That being said, I suspect that the higher temps may also be slightly diminishing the terpenes somewhat as higher temps are know to flash off volitile esthers and flavinoids and whatnot.
As others have mentioned, the PM or bud rot issues that you are experiencing would likely be due to high humidity conditions which you'll need to address.
One tip that doesn't cost any money and can be implemented right away is to always water your plants during the early part of the lights on period and DO NOT water within 4 to 6 hours of lights off.
Humidity levels inside of your tent will always increase once your lights go off. But if you water just before lights off it will cause an excessive increase in humidity levels compared to if the medium were left unsaturated with water overnight. Oh, and do make sure that you keep both your air circulation fans and tent air extraction fan(s) on during lights out to ensure good air circulation and continual fresh air replenishment.
