CMH 315W vs budget Kingbrite QB for cold climate

stonerlibrarian

Active Member
Hi, I have a newbie question. I've been lurking for a few weeks and I'm trying to set up a 3x3 or 2x4 tent (i'm open minded either way) for my first grow for some autoflower seeds i got from a friend and give growing a try. My budget is a bit tight (hours reduced cause of covid). The only space I can grow is my basement. My one issue is i live in a cold climate and my basement usually quite cold especially in the winter when it's -30 out. So now i'm wondering if an LED like the kingbrite 240 or 320 (I was just gonna go cheap with lm301b +epistar660 at 3500k) will keep the tent warm enough. So then I started reading about cmh lights as more sunlike but they produce more heat. I'm wondering if that could be a plus in my cold basement.

There is a local hydroponics shop that has a sale on a budget 315w cmh with lamp for $275 and then i'd get a 3x3 tent no worries about customs fees https://www.tthydroponic.com/index.php?route=product/product&product_id=2096&search=315

Or I've been reading threads about kingbrite in a 2x4 tent. I can get the cheap b+epistar 240w for $210 CAD with shipping and the 320w for $315. https://www.alibaba.com/product-detail/Pre-assemabled-kingbrite-320W-quantum-led_62026740589.html?spm=a2700.icbuShop.41413.11.362a7dafxhoADt

Any advice for a first time grower in a colder basement tent. Which way would you go? Cmh in a 3x3 tent or budget Kingbrite in 2x4? If Kingbrite is 240w enough for a 2x4 or should I get the 320w?

Thank you and sorry if i'm asking too much. I've been reading a lot online but it's a bit overwhelming there are a lot of different opinions out there.
 

stonerlibrarian

Active Member
Thanks for the tips. How much height do i need for a cmh. most budget tents aren't very tall. LIke under 6 feet. Will that not be enough?

I guess the disadvantage is that a cmh will cost more in the long run with power bill and bulbs right?
 

TintEastwood

Well-Known Member
Taller tent better. 6ft min. For cmh.

Determine your grow style and that will help dictate light type and distance from plants.

How many plants, pot sizes, Scrog, SOG, etc.
 

stonerlibrarian

Active Member
If you have the height, cmh may work well.

This has a large diameter vertical reflector. I buy bulbs local. Better in a 3x3 vs 2x4.



Looks like a good deal but even though it's on ebay.ca they say they don't ship to Canada. That's too bad
 

2Hearts

Well-Known Member
No light will change the fact its cold, a 315w cmh wont add much heat to a room unless its really small and even then your fucked at.lightsxoff.

The proper way to do this hobby is to find the right or make the right conditions for an indoor tent or grow.

Somehow mass noob confusion has hid working well in a cold room and led working well in a hot room, not seeing the logic over them both working well in a room that is a constant 70f.
 

PJ Diaz

Well-Known Member
No light will change the fact its cold, a 315w cmh wont add much heat to a room unless its really small and even then your fucked at.lightsxoff.

The proper way to do this hobby is to find the right or make the right conditions for an indoor tent or grow.

Somehow mass noob confusion has hid working well in a cold room and led working well in a hot room, not seeing the logic over them both working well in a room that is a constant 70f.
HID does work better in a colder room than LED, due to the IR radiant heat it puts off, which causes the stomata to open, thereby aiding in photosynthesis. Maybe that clears up the noob confusion for you.

That's not to say that keeping your environment in check isn't of paramount importance, because it is. But, if you have environmental limitations, there is definitely a better choice between the two options.
 

2Hearts

Well-Known Member
Light puts off heat causing stomata to open, the led has more light, ahh i cant be assed explaining the obvious when the point is the basement sounds to cold for any and no lights going to change that so suggest you point out the obvious before wanking over light choice with those on a tight budget.

HID does work better in a colder room than LED, due to the IR radiant heat it puts off, which causes the stomata to open, thereby aiding in photosynthesis. Maybe that clears up the noob confusion for you.

That's not to say that keeping your environment in check isn't of paramount importance, because it is. But, if you have environmental limitations, there is definitely a better choice between the two options.
 

PJ Diaz

Well-Known Member
Light puts off heat causing stomata to open, the led has more light, ahh i cant be assed explaining the obvious when the point is the basement sounds to cold for any and no lights going to change that so suggest you point out the obvious before wanking over light choice with those on a tight budget.
LED puts off very little radiant heat in the form of IR compared to HID. Fact. Yes it will put off heat, but you will need to get the room to a higher overall temp to accomplish what you could at a lower ambient temp with the IR from an HID source. This is why LED growers typically bring their ambien temps to a higher level compared to HID grows.
 

2Hearts

Well-Known Member
No led growers made that up and hps dosent produce much infared suggest there are a ton more efficient sources.

A higher overall temperature, maybe a couple degrees but thats not really a noticable amount and still leaves both lights needing very similar enviroments so less talking rubbish more say it as it is because were not all of the impression leds are as fantastic as your making out, its a light and will need similar to any other light of similar light output.

For a second there i thought i could just throw a hps in the cold outhouse and a led in the boiler room make use of those spacesxwithout the extra heating and cooling.


LED puts off very little radiant heat in the form of IR compared to HID. Fact. Yes it will put off heat, but you will need to get the room to a higher overall temp to accomplish what you could at a lower ambient temp with the IR from an HID source. This is why LED growers typically bring their ambien temps to a higher level compared to HID grows.
 

PadawanWarrior

Well-Known Member
Hi, I have a newbie question. I've been lurking for a few weeks and I'm trying to set up a 3x3 or 2x4 tent (i'm open minded either way) for my first grow for some autoflower seeds i got from a friend and give growing a try. My budget is a bit tight (hours reduced cause of covid). The only space I can grow is my basement. My one issue is i live in a cold climate and my basement usually quite cold especially in the winter when it's -30 out. So now i'm wondering if an LED like the kingbrite 240 or 320 (I was just gonna go cheap with lm301b +epistar660 at 3500k) will keep the tent warm enough. So then I started reading about cmh lights as more sunlike but they produce more heat. I'm wondering if that could be a plus in my cold basement.

There is a local hydroponics shop that has a sale on a budget 315w cmh with lamp for $275 and then i'd get a 3x3 tent no worries about customs fees https://www.tthydroponic.com/index.php?route=product/product&product_id=2096&search=315

Or I've been reading threads about kingbrite in a 2x4 tent. I can get the cheap b+epistar 240w for $210 CAD with shipping and the 320w for $315. https://www.alibaba.com/product-detail/Pre-assemabled-kingbrite-320W-quantum-led_62026740589.html?spm=a2700.icbuShop.41413.11.362a7dafxhoADt

Any advice for a first time grower in a colder basement tent. Which way would you go? Cmh in a 3x3 tent or budget Kingbrite in 2x4? If Kingbrite is 240w enough for a 2x4 or should I get the 320w?

Thank you and sorry if i'm asking too much. I've been reading a lot online but it's a bit overwhelming there are a lot of different opinions out there.
These are great. Get the 3100k though. I have 2. I also have HLG LED's, but my favorite is a combo of both. I just can't run the cmh as much in the summer. You have the perfect environment for the cmh though.

The cmh also gives off UV rays too, which the LED doesn't.
 
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PJ Diaz

Well-Known Member
No led growers made that up and hps dosent produce much infared suggest there are a ton more efficient sources.

A higher overall temperature, maybe a couple degrees but thats not really a noticable amount and still leaves both lights needing very similar enviroments so less talking rubbish more say it as it is because were not all of the impression leds are as fantastic as your making out, its a light and will need similar to any other light of similar light output.

For a second there i thought i could just throw a hps in the cold outhouse and a led in the boiler room make use of those spacesxwithout the extra heating and cooling.
You don't think that the HID produces much IR likely because they always cut the charts off to show only the visible spectrum. Here is a better chart showing the complete spectrum (including IR) of multiple HID lamps, and as you can see there's a pretty significant spike around 820nm on virtually every lamp:


Sure, of course you need to get your environment in check, as I mentioned in my first post. But if you use HID perhaps only a 10 degree increase is necessary, while with LED you may need to increase the temps over 15 degrees. In cases like that you might just want to get the IR working for you.

Having grown with HPS for years and just switched to LED in the past year, I can definitely say that plants like different environments under the two different light sources.
 

Rocket Soul

Well-Known Member
Light puts off heat causing stomata to open, the led has more light, ahh i cant be assed explaining the obvious when the point is the basement sounds to cold for any and no lights going to change that so suggest you point out the obvious before wanking over light choice with those on a tight budget.
What led and with what intensity do you use at 70F? With what humidity? And what nutrient concentration? Hydro or soil? Im seriously interested and not picking a fight. In my experience the amount of heat coming from a white based led light is not really enough to drive transpiration hard enough to keep the plant with proper nute levels. Generally you see mag defs and bleaching and poor plant stance. But ive never run blurple or high K spectrums with a lot of blue.

If its possible id love to know how, it would make the grow so much easier
 

2Hearts

Well-Known Member
Light is a packet of energy, whatever absorbs it gets warmed, your trying to seperate that tiny amount of ir in hps or cmh and basing transpiration of it and not all the other combined light.

Take the ir from a 315 or 400w hps - now produce the same amount without the light and see just how little it heats a tent let aloneca small room.

Leds are and always were sold on guesswork, hps is hot so it must be the ir duh, lets leave that out of led and now we can run it in rooms that are too hot for all the other lights duh. Yer do some science first before you sell me an led.


What led and with what intensity do you use at 70F? With what humidity? And what nutrient concentration? Hydro or soil? Im seriously interested and not picking a fight. In my experience the amount of heat coming from a white based led light is not really enough to drive transpiration hard enough to keep the plant with proper nute levels. Generally you see mag defs and bleaching and poor plant stance. But ive never run blurple or high K spectrums with a lot of blue.

If its possible id love to know how, it would make the grow so much easier
 

2Hearts

Well-Known Member
That whole light bearing spectrum andcthat tiny amount of ir equals 10degrees, are you even on thos planet, by that equation the rest of the light would hit about 200-400f increase in temp.

Ffs and omg!


You don't think that the HID produces much IR likely because they always cut the charts off to show only the visible spectrum. Here is a better chart showing the complete spectrum (including IR) of multiple HID lamps, and as you can see there's a pretty significant spike around 820nm on virtually every lamp:


Sure, of course you need to get your environment in check, as I mentioned in my first post. But if you use HID perhaps only a 10 degree increase is necessary, while with LED you may need to increase the temps over 15 degrees. In cases like that you might just want to get the IR working for you.

Having grown with HPS for years and just switched to LED in the past year, I can definitely say that plants like different environments under the two different light sources.
 

Rocket Soul

Well-Known Member
Light is a packet of energy, whatever absorbs it gets warmed, your trying to seperate that tiny amount of ir in hps or cmh and basing transpiration of it and not all the other combined light.

Take the ir from a 315 or 400w hps - now produce the same amount without the light and see just how little it heats a tent let aloneca small room.

Leds are and always were sold on guesswork, hps is hot so it must be the ir duh, lets leave that out of led and now we can run it in rooms that are too hot for all the other lights duh. Yer do some science first before you sell me an led.
So what youre saying is that you havent tried led? Im not selling just trying to figure out how you grow at 70F with 800ppfd of white light. Can you show how?

You know its not about what the ir does to the tents temp its the leaf temp?
 

PadawanWarrior

Well-Known Member
That whole light bearing spectrum andcthat tiny amount of ir equals 10degrees, are you even on thos planet, by that equation the rest of the light would hit about 200-400f increase in temp.

Ffs and omg!
Which planet are we talking about? Sounds like Mercury.

It does get hot here and my crops do have a hard time. My AC's can keep the temps to a manageable 300 or so degrees, but I can't get it any lower. Still growing fire.
 

Rocket Soul

Well-Known Member
That whole light bearing spectrum andcthat tiny amount of ir equals 10degrees, are you even on thos planet, by that equation the rest of the light would hit about 200-400f increase in temp.

Ffs and omg!
I think your missing the point, having leaves warmer than ambient or colder than ambient changes transpiration drastically and will also affect the rate of metabolism. Have a look at vapour pressure deficit and see what happens if you change the leaf temps:

This is one of the major drivers (but not the only one) of trranspiration : without water and nutes the plant simply cant keep up
 
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