What's more important: maxing LED intensity or staying within temperature range?

I'm about to start my first grow and I am growing in a very small kitchen cabinet with a 100 watt quantum board. But I misjudged how much exhaust ventilation is needed to keep temperatures in check, so I can't put the lamp on maximum intensity without overheating the grow space.


What would you recommend:

1) Put the lamp on 60% intensity so that temperature doesn't go above 28 degrees celcius
2) Put the lamp on 70% or even 80% intensity and just accept that temperatures will be 29-30 degrees celcius


I guess what I really am asking, is how important are temperature ranges compared to light intensity?
 

desplegado

Well-Known Member
I'm about to start my first grow and I am growing in a very small kitchen cabinet with a 100 watt quantum board. But I misjudged how much exhaust ventilation is needed to keep temperatures in check, so I can't put the lamp on maximum intensity without overheating the grow space.


What would you recommend:

1) Put the lamp on 60% intensity so that temperature doesn't go above 28 degrees celcius
2) Put the lamp on 70% or even 80% intensity and just accept that temperatures will be 29-30 degrees celcius


I guess what I really am asking, is how important are temperature ranges compared to light intensity?
If ur starting from seed idk if u want it at 60% i recommend 20-30% 10-15 inch above and turn light up as it grows
 

strops

Member
i have my led 24" from plants at 75% intensity gives me 26-28c. Once plants go to flower i'll move led 17" from plants at 100% intensity. while they young and in veg mode they dont need full light.
 

conor c

Well-Known Member
I'm about to start my first grow and I am growing in a very small kitchen cabinet with a 100 watt quantum board. But I misjudged how much exhaust ventilation is needed to keep temperatures in check, so I can't put the lamp on maximum intensity without overheating the grow space.


What would you recommend:

1) Put the lamp on 60% intensity so that temperature doesn't go above 28 degrees celcius
2) Put the lamp on 70% or even 80% intensity and just accept that temperatures will be 29-30 degrees celcius


I guess what I really am asking, is how important are temperature ranges compared to light intensity?
Not a led guy however I know that would depend on your light alot of them you can't run full power or you will cook it all id say run it with what u can get away with don't go overboard just find the best balance you can between light intensity/temps
 

Delps8

Well-Known Member
I'm about to start my first grow and I am growing in a very small kitchen cabinet with a 100 watt quantum board. But I misjudged how much exhaust ventilation is needed to keep temperatures in check, so I can't put the lamp on maximum intensity without overheating the grow space.


What would you recommend:

1) Put the lamp on 60% intensity so that temperature doesn't go above 28 degrees celcius
2) Put the lamp on 70% or even 80% intensity and just accept that temperatures will be 29-30 degrees celcius


I guess what I really am asking, is how important are temperature ranges compared to light intensity?
If you can't ventilate the grow area, that's going to make things tricky.

You should keep temps at the canopy <30/85 degrees for germination, seedlings, veg, and into the second week in flower. After that, 85° will severely reduce the amount of cannabanoids, so you should get temp ≤25/78°

In terms of light, a light meter solves a lot of problems. Lacking that, we can estimate PPFD from dimmer setting and light make and model (100 watt quantum board) but hang height is the other part of the equation.

How far above the plant do you hang your light?

As a seedling, you can drop the hang height to, say, 12" and, at that height, I wouldn't give a plant more than about 25% power.
 

coreywebster

Well-Known Member
Great, good to know, because it seems like I'll be pushing 29-30 degrees celcius most of the time.




It's a 40x40x100cm (1.5ft by 1.5t by 3.5ft) IKEA METOD kitchen cabinet.
40cm is 1.37ft so 1.8769²ft
In flower @30w per ²ft that's 56w
Or @40w per ²ft that's 75w

So you don't need it over 75%
 

joesoap2013

Well-Known Member
Funny how plants take it fine with led but with hps id be freaking out if my temps were that high I like running cooler in bloom anyway
Know what you mean man
I had problems switching to an led what I am doing is turn the light to say 60 percent move it further away have a fan blowing the heat off the light down onto the leaves
It's the vpd in the leaves the hps bulb heats the leaves up
in a normal room a leaf will be a couple of degrees cooler than the room itsel so you have to heat the room up for the leaf to be the right temp the owl bulb contracts it know what I mean
The leaves arnt a couple of degrees cooler causr of the bulb heat
 
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