A Heated Debate??

I'm hearing a few different things on ideal temps for my grow box. I think I've managed to dial in on about 82*F consistently. Some are telling me this is a good place to be at while others are saying I should be aiming for about 75*F.

Anyone got anything legitimate to say on this?

82 is fine but really on the edge of what you want, I prefer to be between 75 and 80 but you are good to go at 82.

Are you talking veg or flower temps? The two have different recomended temps. Low 80's in veg and mid to lower 70's in flower.

topfuel29 said:

Are you talking veg or flower temps? The two have different recomended temps. Low 80's in veg and mid to lower 70's in flower.

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Which more closely resembles what happens in nature.

cuttings and clones 79 -81 degrees. veg 79- 81 degrees. and flower is 74-78 depending on the co2 in the room.

In my opinion all these numbers are just a basic guidelines. There are so many different plants from different climates that a consistent temp of 75 just isn't always the best. Some strains like 70-75, others like 75-85. Right now I'm growing space from world of seeds; they definitely like 80-85 with humidity anywhere from 25-60! It's a wide margin I know, but anything higher or lower and the leaves start to droop within 90 minutes. Plants are living things and not all living things thrive in the same environment. A grizzly Bear wouldn't do so well where polar bears live. Same species, different conditions required. I'm not saying, for example, my space girls won't live through 70 degree temps, but they are doing better at 80-85.

I run 76-82..... Iwold sy your at the top of the ladder, don't fall off

I have my best results from 72-75 in flower and 75-78 in veg. but thats just what work good for me. if you got a good CO2 setup you can run high temps better

No CO2 set up. Right now I'm in veg but plan on flowering very soon so I would like to drop the temps a fair bit. This weekend I'm picking up a small osc fan and hoping that helps. Maybe add another intake vent hole.

buster8813 said:

In my opinion all these numbers are just a basic guidelines. There are so many different plants from different climates that a consistent temp of 75 just isn't always the best. Some strains like 70-75, others like 75-85. Right now I'm growing space from world of seeds; they definitely like 80-85 with humidity anywhere from 25-60! It's a wide margin I know, but anything higher or lower and the leaves start to droop within 90 minutes. Plants are living things and not all living things thrive in the same environment. A grizzly Bear wouldn't do so well where polar bears live. Same species, different conditions required. I'm not saying, for example, my space girls won't live through 70 degree temps, but they are doing better at 80-85.

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This makes sense. Ok so lets say I don't know what strain I have and therefore don't know what the happy range is, is there any sure method you can go by to figure out where the gals are happiest? My worry is I'll be told trial and error. Just tweak a few things and watch out for signs of stress, right? Easier said then done lol.

But I do know the strain. Nirvana's northern lights. Any insight?

Ok, so moved my box to a colder area of the house. Like way colder. The lights are the only heat source and right now it's actually sitting around 75. Much safer now, right? Here's where my questions take a complete flip. Let's say I decide to go to flower soon. After 12 hrs the lights go off and all the heat escapes. It would drop to below 70 where I've got it. What's an ideal low night temp? Should I be putting a heat rock in there or something? How cold is too cold or what is 'ideal' cold?

I've read a few forums talking about plants surviving to below 30 even but most posts were from outdoor growers and it's just not the same scenario, right? Plus I think that would slow progress, am I right? Basically I can't find if there is an "ideal" lights-off temp. (I'm running 24hrs in veg right now btw)

JayDiggz said:

Ok, so moved my box to a colder area of the house. Like way colder. The lights are the only heat source and right now it's actually sitting around 75. Much safer now, right? Here's where my questions take a complete flip. Let's say I decide to go to flower soon. After 12 hrs the lights go off and all the heat escapes. It would drop to below 70 where I've got it. What's an ideal low night temp? Should I be putting a heat rock in there or something? How cold is too cold or what is 'ideal' cold?

I've read a few forums talking about plants surviving to below 30 even but most posts were from outdoor growers and it's just not the same scenario, right? Plus I think that would slow progress, am I right? Basically I can't find if there is an "ideal" lights-off temp. (I'm running 24hrs in veg right now btw)

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I kinda have that problem right now ( low temp) and I've been dealing with it all winter here. The problem is when you go below 70 or so in temp, they'll survive it, but growth slows down to a crawl.

Here's the way I look at it. Indica strains originate from countries like Iraq and Afghanistan. You can have 90+ heat during the day and 50f during night. Sativa's on the other hand originate in more equatorial conditions, so between 80 for day and 70+ for night is best.


So keep it above 65f and you'll be fine

plants will thrive in a hotter environment if you can supply enough fresh air / co2 water and nutes
this works much better with hydroponics , in hotter temps when the enviroment is well dialed in the plants drink more eat more and grow faster
75f is possibly ideal for soil grown plants, that may have problems at hotter temps keeping themselves cool through the lack of a constant water supply, and a lack of a constant food supply

i would keep it at 80-85 for hydro, 85-90 for co2 enriched
although co2 is ideal, using an active inlet bringing fresh air from directly outside, and ducting it straight to your plants
works very well compared to a passive inlet

your plants will tell you if they are too hot, the leaves will fold themselves or curl at the sides
if you hold the surface of the top leaves closet to the light they should feel cold
if they feel warm, the plant is not able to cool itself down quick enough and the environment is too hot

peace

I love this site. You guys rock.

the root zone temp is what you gotta watch. roots to hot = bad roots to cold = bad. out doors plants can handle almost freezing because there roots are in the ground and the temp of the ground keeps them warm,

same thing in the summer time when it is 100 out side the plants roots are in the ground and the ground keeps them cool.

indoors is tricky because you are incharge of the root temp. dont go below 55