I might have a serious problem about to develop, I didn’t know where to post this so I put it here because I’m 4 weeks into flowering. My grow room is in the attic over an un airconditioned shop. There is going to be a heat wave over 100 degrees centigrade and I’m expecting the grow room to reach temps around 120. I need to know how to change the lighting from 12-12 on during the day to having the lights on at night to help with the temperature. I am planning on watering 3 or 4 times at around 1 liter each time to help the plants. This high temp will be for 3 days during the day so I an trying everything to get the plants through this without losing the flower or even worse the grow. These are White Widow plants growing in 5 gallon bags. can they withstand 3 days at these temps? and can you think of anything else I can do to help them get through these 3 days of high temps. Any help or ideas would be appreciated as I can’t move the plants out of the attic due to weight and size.
120 celsius is like 250 f and half that much heat will kill your plants do you are gonna need some ac
When the lights come on, just change the light schedule. They will do fine with the additional dark time that they will receive. Don’t worry to much about the light schedule. You are thinking in the right direction having the lights on during the night time but may need to add some additional cooling to keep the temperature in check.
I’m sure you meant 100 F?
I doubt that one single time change will matter. Just move it to 12/12 on during night. What time do lights come on now? Are you ready to flip at all?
Tell us more about your grow space. Would you have the option to get a small portable window A/C unit? I put mine outside the tent, made a makeshift vent/hookup so it vented the AC OUTSIDE of the tent, but forced the cold air in through one of the vents in the tent. Around that vent, you can use a cardboard box (I used an actual register vent), cut a hole in the middle to feed the hose through. tape it all up and tape it to the tent.
I don’t have a pic of mine but this is basically what you can do. Take this basic pic, add a flex hose so reach the vent hole in your tent, then another register vent only reversed (wide side up against the vent hole in the tent.
I also am about to hit triple digits for next month or so. I will flip over to a 6pm to 6am schedule probably today. Maybe. Depends on if i get off my butt. Temps hitting mid 90f for a couple days wont killem. Nature pushes them harder than that. I suggest just watch your water. Keep good airflow and flippem to an overnight schedule. Temps steady mid 80-to low 90s are common for me. I stopped fighting it as I learned to adjust my watering and airflow to compensate. Cannabis is tough. Perfection is unattainable for most home growers unless you spend your car and mortgage payments to buy the best setup that truly is not needed for us. Just my thoughts.
I would make sure you have some fans going to circulate the air. Best of luck.
Yep, heat index of about 110°F here the next few days. Even at night with lights on, im still averaging 81°F thats with ac running.
Thanks everyone, I will do my best to control the temp, I can’t use any AC but I might even haul bags of ice to help. This heat is only for 3 days then it will be back to low 90’s and high 80’s which is what they are used to. If you think of anything please let me know. I was thinking about less water more often during the 3 days of high temp. If I shouldn’t do this please let me know. Would it hurt to use less light for a few days? One thing I have is plenty of light for flowering.
A cooler full of ice with a fan blowing over the top…
I was thinking about using dry ice with a fan blowing over it when the temp hits 110 degrees fahrenheit, I might have used the wrong term in the PO. If this isn’t a good idea please tell me. I don’t thin the carbon dioxide would hurt the plants.
Right now my 12-12 schedule is 8 AM to 8 PM I will leave the lights out for 22 hours and change to 6 PM to 6 AM.
Could freeze water in 2 liter bottles or gal jugs and place around or better yet, freeze water in a small tote or something with no lid. spread some salt on top of ice and use the fan to blow across it. Salt will mix with the melting ice and lower the surface temp by a BUNCH. Dunno, just thinking out loud.
I am doing 8 PM to 8 AM also for lights on now.
We made it through the heat wave and now dealing with humidity as we cure the buds. Thanks again everyone, it great having all the experience here to ask questions.