Co2 and heat

Temps have sky rocketed and room is suffering, plants look fine i run co2 about 2500 ppm usually temps are around 78-80 but cant get temps down due to exterrior heat witht he extra heat should i turn co2 up a bit or let it ride and watch for heat stress ? They are 3 weeks into flower.

What's your RH? They can take some heat. 3 weeks into flower you should be OK as far as bud rot. CO2 an expensive fix.

I run co2 anyways its a sealed room. rh is 30%

Da fuck?
Turn the CO2 down, more then 1500 is to much.
Your temp is fine,

I run 1100-1300ppm from 45min after lights on till about 1.5 hours before the turn off.
I keep my Day time temp between 80-85
Night is around 70-75
RH is 50%
Day35
Seed run with 4 different pheno
That’s y the canopy is very uneven

Yeah, no need to go over 1500ppm... 80*F is fine w/ CO2... can go higher...

I do like to bring down the temp, RH and CO2 a little after the stretch.

Sorry let me rephrase that normal temps are around 78-80 with my ac malfunction im about 92-94. Got new ac on the way just going to be about a week before i can get it and install

If you look at the 2 charts above, the top one states max photosynthesis occurs around 37*C (99*F) leaf temp, the bottom one states max photosynthesis occurs around 44*C (111*F) leaf temp in C3 plants... that's a huge difference... unfortunately the data doesn't seem to be consistent but it shows that higher temps with CO2 is okay. Keep in mind, this is leaf temp, not ambient...

https://www.maximumyield.com/the-relationship-between-leaf-surface-temperature-and-lighting-spectrum/2/3226

I've grown in temps that high with no extra CO2 and a LOT of circulation... weren't the tightest buds... but they weren't bad at all... I would think w/ CO2 you might be ok, but I'm not an expert on it.

Hopefully someone will chime in.

What kinda lighting you running?

SSR said:

What kinda lighting you running?

Click to expand...

600 w hps

They are not showing any signs of heat stress, actually looking decent

Not much option for dimming to help drop the temps then and id say your about at the limit tbf.
If you're running your lights during the day I'd give a longer night period so you can start running your light at night when it's cooler, that'll help reduce stress a bit.

Id drop your CO² as mentioned but only to save a bit of money.
Id try and increase airflow if you can and keep em watered so they can transpire to help with the heat (if they haven't closed everything up due to the heat already).
As said being so early in flower the plants should be ok.
I wouldnt worry if its a couple days but if the temps get much higher

Not a ton of help but ill keep my fingers crossed for ya

Ya i dimmed down from super hps, to just the 600 , im running from 7 pm to 7 am temps outside have been 99_106 for last week supposed to be cooler this week get new ac next weekend about to hook my other fan up pop the ducting off one side of light and run unsealed for this week

I wouldn't run unsealed tbh.
The CO² is saving you at those temperatures, keep the room sealed and venting the hood

Edited to add:
Those outside temps are mad btw, glad its not me there lol.
You could vent the room if you have house A/C but that could bring it in problems.

Is your hood insulated?

Ya i vent into house and my gf would be the problem bahahha. ill just roll with it drop co2 down a smudge. Got deminsions for new ac so i can get that ready to go so no waiting. Thank you for input
Ya heat is a killer out her but thankfully its dry so dont have tje humidity issues

Best of luck, hopefully it cools a bit for you soon

Got new ac installed temps back down in high 70 got another month are so to go so hopefully they start filling out now thanks for support.