# High temps during dark phase



## iamtd (Nov 24, 2009)

Hello all.

I bought a wireless temp and humidity meter today. My Temp at the moment 4 hours into the light cycle is 29.7C (86.45F) and my humidity is 53%. My only problem is I think the room is getting hotter during the day (the plants dark period) upto about 32C-33C. (89.6F-91.4F) I've been reading that there should be at least a 10 degree drop in temp during the dark cycle. Is this going to affect my plants growth?

Also here is a link to my grow if you wanna check it out and give me any ideas or advice. Thanks. 

http://www.marijuanapassion.com/forum/showthread.php?t=49927


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## ozzydiodude (Nov 24, 2009)

IMO you need more ventalation your temps should be no higher than 80* with the lights on and around 70* with lights off.


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## iamtd (Nov 24, 2009)

Its going to be very difficult for me, without use of a/c with the grow in a grow box in my garage and ambient temp reaching 35C (95F) within my garage during the day. The ambient temp is around 25C (77F) during the night during my light phase. Its just to damn hot atm to be running the lights during the day, and a/c isn't really an option as this is a more a hobby then anything else for me.

What are the effects of running at these semi-high temps, and having the room hotter during the dark phase?

The only economically sound way around this for me is DIY insulation for my garage????


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## DonJones (Nov 25, 2009)

Ventilating the garage might help and but I'm afraid that you are probably going to nee dot bite the bullet and go to AC.  Even as a hobby, growing 5 oz or more will certainly save you enough to pay for the AC, and the expense is primarily a one time purchase and a slight increase in electricity while the savings keep on accumulating as long as you grow.

Just a though- how high is the humidity where you are, which I think is in the Southern Hemisphere given those temp at this time of year?  How good of a water supply do you have?  Check into Swamp coolers.  They are a lot cheaper than big AC units.  for a 1 square meter grow room a very small AC unit would work but a swamp cooler cooling the entire garage would be a better idea.  If the temps in the garage are that high, no amount of ventilation will solve your problem, but personally I would install an intake vent or fan if you don't already have one.  Remember pot grows wild in some very hot climates, so your plants will probably survive and grow but probably not as well as if you can get you temps down.  I'm sure that having the temps higher in the dark probably will effect them more than the temps, but I don't know because I haven't ever heard of the results of this reversal.

The temp of your solution is probably more critical than the air temps though because you can cook the roots easier than the foliage.  From what I have read the the solution temp goes critical at about 80F and should be under that.

Good smoking and I hope some ones comes up with some good ideas.  Happy Thanksgiving.


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## ASEgrower (Nov 25, 2009)

DonJones said:
			
		

> Ventilating the garage might help and but I'm afraid that you are probably going to nee dot bite the bullet and go to AC. Even as a hobby, growing 5 oz or more will certainly save you enough to pay for the AC, and the expense is primarily a one time purchase and a slight increase in electricity while the savings keep on accumulating as long as you grow.
> 
> Just a though- how high is the humidity where you are, which I think is in the Southern Hemisphere given those temp at this time of year? How good of a water supply do you have? Check into Swamp coolers. They are a lot cheaper than big AC units. for a 1 square meter grow room a very small AC unit would work but a swamp cooler cooling the entire garage would be a better idea. If the temps in the garage are that high, no amount of ventilation will solve your problem, but personally I would install an intake vent or fan if you don't already have one. Remember pot grows wild in some very hot climates, so your plants will probably survive and grow but probably not as well as if you can get you temps down. I'm sure that having the temps higher in the dark probably will effect them more than the temps, but I don't know because I haven't ever heard of the results of this reversal.
> 
> ...


 
May be a moisture issue with a swamper


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## ozzydiodude (Nov 25, 2009)

IMO with those high temp if you are running a swamp cooler and exuasting the grow room air outside your RH should not be a problem


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## DonJones (Nov 26, 2009)

I agree with ozzydiodude.  Unless you have used a swamp cooler, especially with a high volume of air flow, you can't even imagine how effective they are, even in humid climates.  I know I use done once out of desperation and was totally blown away by the results.  It cooled na entire poorly insulated 2 bedroom house in 100F weather.  Until the last few years, they were the standard AC in homes.

Too little air flow is a more common cause of mold and mildew than just high humidity.

Good smoking and Happy Thanksgiving.


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## dman1234 (Nov 26, 2009)

But  86 f is not a big deal with good air flow.


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## DonJones (Nov 26, 2009)

If 86F was his high temp, I would agree BUT this in his low temps.  His high temps are above 90Fand that is in the dark when it should be the lowest not the highest.

When my temp in my first grow was getting to 85F or higher, the plants didn't grow as fast or as well as after I got it down to 80F and below, and I had a whole lot of air flow, but maybe not enough air exchanges because that was how I lower the temp -- by increasing the amount of in coming and out going air rather than just using fans to move it around, but that Isn't going to work for him because his outside is real hot.

Good smoking.


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## dman1234 (Nov 26, 2009)

agreed, but how can lights on be his low temp?

that confusses me..............

and get rid of the computer fan as an exhaust, thats his problem rite there.


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## DonJones (Nov 26, 2009)

Okay, I under stand how that is confusing because most people run their lights in the daytime to make any light leakage less noticeable and to give them more access to their plants, and turn them off at night when it is already cooler outside plus their lights aren't adding heat to the room eithr so normally the dark period is the cooler period.  BUT in this case, and like a lot of growers in hot country, iamtd is growing in an area where the daytime outside temperatures are way above 90F -  probably closer to 100F in the daytime and down into the mid to high 70s at night, so he runs his lights AT NIGHT when the outside temperature is lower so that he can remove more of the heat from the lights.  His darkness period is in the daytime rather than the night.  During the night he has outside air cooler than 80F that he can circulate through the room to try to keep the lighted room cooler BUT during the day, which is also his lights off-dark period in the room, the outside temp is near 100F so he has no way to cool or ventilate the room except figuring some kind of AC.

Even super insulating his room will only be of limited help because he still needs to move outside air through the room for CO2/O2 exchange and bringing hot air into the room will cancel out the effectiveness of the insulation.

I did I explain it right or are you still confused?  My explanations are not always as clear to others as I think they are.


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## Kupunakane (Nov 26, 2009)

You Know,

   One area where you guys have not even strayed into is the thought that there are many strains of Marijuana that come from all over the planet. 
  There are a great many strains that would love that high heat and humidity, and they really would do well. Perhaps you might consider this as a viable direction, before you drive yourself nuts trying for something you already have, and that is the ability to grow. Just my $0.02


smoke in peace
KK


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## PUFF MONKEY (Nov 26, 2009)

dman1234 said:
			
		

> agreed, but how can lights on be his low temp?
> 
> that confusses me..............
> 
> and get rid of the computer fan as an exhaust, thats his problem rite there.


cause they run at night ???


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## RiskyPack (Nov 27, 2009)

I don't really believe the drop in temps are really necessary... My plants are doing fine, and there is only a small drop in temps here.. And I know that when I lived in India the plants were growing outside in 37 degrees Celsius at daytime and 32 at night, with a humidity close to 100.. I really don't think you should worry too much unless your plants start looking stressed.


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## iamtd (Dec 1, 2009)

Wow. I wish i had of checked this thread a few days back. I thought it was dead. Thanks for all your input guys. DonJones your exactly right. I run my lights at night so that i can keep the temps down why the lights on. Also as i work during the day and most of the night, it allows me to be able to access my room and do the things i need to do when i get home from work.

www,marijuanapassion.com/forum/showthread.php?t=50216
(wont let me link to the page for some reason)

Here is a link to my latest post and photo's. As you can see i have installed a cool tube to get the temps down even more. I have bought a temp probe as well. I'm getting my temps down to around 77F during the night now with humidity between 50% and 60%.

My day-time temps are still really up to the forces of nature. Right now its at 80.1oF outside and 76F inside. But its an overcast and cool day. On a regular day ATM, ambient temps are around 93F, in the next month and a bit, that may raise to 100F. My room is sitting a few degrees below the ambient temp. 

My resivour temp is at a happy 76F-80F at all time.

Thanks DonJones for the tip about the swamp cooler. I don't know what they are. But I'll look into it now. I'm guessing an evaporation cooler?

Thanks again, and sorry about replying so late.


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## ozzydiodude (Dec 1, 2009)

Here is a good explanation of swamp coolers

hxxp://www.consumerenergycenter.org/home/heating_cooling/evaporative.html


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## iamtd (Dec 1, 2009)

Thanks ozzydiodude.

I'm thinking if i could one small enough. I could just sit it in front of the intake essentially blowing air into the cab? Also thinking i could plug it into an external thermostat to turn on at x degrees and off at x degrees. Could be a fairly cheap option.

And dman1234, I have a 250mm Exhaust fan in the roof. That computer fan was just a bad attempt at air cooling the light. I have since then bought a cool tube proper. So I'm exhausting from the top with the 250mm and from the cool tube with the computer fan. Temps are looking a lot better during the light cycle.


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## dman1234 (Dec 2, 2009)

glad to hear things are working out.

watch humidity with a swamp cooler


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## iamtd (Dec 3, 2009)

I will. Luckily is been a little cooler the last couple of days. Thanks for the help guys!


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## pcduck (Dec 3, 2009)

> My resivour temp is at a happy 76F-80F at all time.



I do not know what type of media you are using but if doing hydro(ebb/flow, dwc, or nft).

Your reservoir is not happy

Water temps should be 66f-68f or around there, at least 70f or under.


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## iamtd (Dec 3, 2009)

Sorry thats my bad. I converted wrong. It sits between 21C(69.8F) and 23C(73.4F) Its almost feels too cold when i put my hand in. I use a PPM a Temp Meter. And if you look at my links you will see i do ebb and flow with clay medium in 9' netted pots.

Thanks pcduck!

I have also been trying to read about watering. How often should i flood the tray and when? I currently flood for 15 minutes every 4 hours spread evenly across the day. But i was wondering if i should flood less during the dark phase or not at all?

Idea's?


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## TURKEYNECK (Dec 3, 2009)

Ive used rockwool starter plugs in 6" pots of hydroton and I flooded every three hours for a total of eight times a day.. they need to drink at night too

The amount of times you flood in a day all depends on your medium...


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## iamtd (Dec 3, 2009)

Thanks for letting me know to water at night TURKEYNECK. Thats fact has been eluding me for a while now.


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## TURKEYNECK (Dec 5, 2009)

iamtd said:
			
		

> Thanks for letting me know to water at night TURKEYNECK. Thats fact has been eluding me for a while now.


 
No problemo. We're all here to help each other improve.. Goodluck


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## iamtd (Dec 6, 2009)

That we are. If i could only find a thread where *I* could help! :aok:


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