CMH Light Distance????

Gregzky

Active Member

Oct 10, 2019

• #1

Hey Guys,
I just bought a 315 w ceramic metal halide light to replace my LED.
How close do I want that light on my 4 week old plants? It throws off pretty good heat compared to the LED.

 

Hugo Phurst

Well-Known Member

Oct 11, 2019

• #2

IMO - minimum of 24 inches. I got kinda tired of moving lights every couple of days so now I just keep them just shy of max height.

Or - Put your hand under the lamp until it get uncomfortably hot, them slowly move your hand away till it's an easily tolerated warm, that's min distance.

 

Gregzky

Active Member

Oct 11, 2019

• #3

Okay ,thanks!

 

TintEastwood

Well-Known Member

Oct 11, 2019

• #4

Here's what happens if too close in late flower.

 

diggs99

Well-Known Member

Oct 13, 2019

• #5

I use the hand test with the 315 I'm running.

I'm currently flowering 2 cup plants under it and right now the light is approximately 14" from the top of the biggest gal.

Here's a pic

 

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Gregzky

Active Member

Oct 13, 2019

• #6

Ok that’s what did. However one of mine was shows curling on a couple 3 top leaves. They’re young still. The other leaves look fine so it should recover.

 

turbobuzz

Well-Known Member

Oct 13, 2019

• #7

Agree that 20 to 24 inches seems to be the sweet spot for mine.

 

Gregzky

Active Member

Oct 13, 2019

• #8

How old are yours that you have it 20-24 inches above ?