Required CMH Wattage Per Square Foot?

Logan Burke

Logan Burke

Well-Known Member
Hello everyone, I was just curious if anyone around RIU knew how many watts of CMH lighting per square foot is ideal? I am starting up a new, quite small vegging tent and am curious if a single 315w CMH fixture will be adequate. The tent size is 2ft x 4ft x 5 ft tall. Appreciate any and all input everyone, happy growing!
*EDIT* Meant to add, there will only be two plants in this tent.
 
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OldMedUser

OldMedUser

Well-Known Member
From what I've seen of the 315 units the reflector has a rather small footprint so you'd probably be a little short of light out on the 4ft sides. With that short a tent you will need to train well or go with a ScroG setup to keep the canopy low and flat.

You might want a couple of LED strips or other lighting to fill in the long edges or even better a light mover to get the CMH to cover it all. I got a Light Rail about 3 years ago and love it. They aren't cheap but save tons of power over running a 2nd light.

If all you're going to do in that tent is veg and can move the plants around to share the sweet spot then the 315 should be plenty on it's own.

:peace:
 
Logan Burke

Logan Burke

Well-Known Member
Yes I'm only using this tent to get the two plants ready for the light schedule flip to 12/12, and yes the heigth is very concerning too me, but because they won't be doing their full 'stretch' in this tent I am hoping that this won't be a problem. I appreciate the reply a bunch OldMedUser!!! I about forgot to mention, I am getting a CMH fixture with the attatchment that allows it to be aircooled. I am hoping that this will help if the plants get too tall, although I know cooling a CMH bulb does affect color spectrum. Right now, the height is the issue that has me sweating haha. But worst case scenario, they'll just have to go back into the big flowering tent sooner than later.
 
diggs99

diggs99

Well-Known Member
I was told by the guys in the 315 lec thread that 2x 315s will flower a 3x6 foot print. So 3x3 for each light . Should be a little bigger for veg I assume?

Best place to ask this question is the 315 lec thread. They gave me a lot of help, answering similar questions as you have.

Best of luck with it
 
Logan Burke

Logan Burke

Well-Known Member
Really appreciate the information everyone, I've been curious about LEC's for years now and I'm thrilled to get my feet wet finally! I'll be sure to grab the 4200k Rky, thanks!
 
JoeBlow5823

JoeBlow5823

Well-Known Member
NukaKola said:
What are the dimensions of the tent? A 315w CMH & 120w LED would be nice.
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40''x40''. Kind of an odd ball size but will fit perfectly where its going. I got a gorilla tent and that was a huge mistake. This will be replacing that tent. No led for me. Might do one 315cmh and one 150hps. But I really wanna try two 315's up nice and high so i get good even light coverage.
 
PadawanWarrior

PadawanWarrior

Well-Known Member
JoeBlow5823 said:
40''x40''. Kind of an odd ball size but will fit perfectly where its going. I got a gorilla tent and that was a huge mistake. This will be replacing that tent. No led for me. Might do one 315cmh and one 150hps. But I really wanna try two 315's up nice and high so i get good even light coverage.
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Why was the Gorilla tent a huge mistake?
 
Renfro

Renfro

Well-Known Member
JoeBlow5823 said:
5. yes you read that right 5. five. cinco. 555555555. 5 god damn zippers to open the front of it. Plus a bunch of velcro flaps. Its insane. Sure its light PROOF. but its so stupid opening and closing it that I just leave it open.
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I guess I don't have a problem with zippers, I am definitely as lazy as they come and I manage to close my tent. I guess it's a good thing blue jeans only have one zipper... lol
 
JoeBlow5823

JoeBlow5823

Well-Known Member
Renfro said:
I guess I don't have a problem with zippers, I am definitely as lazy as they come and I manage to close my tent. I guess it's a good thing blue jeans only have one zipper... lol
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My biggest issue is the middle zipper because you have to re-zip it like a coat every time you put it on. And then all the flaps/velcro that are in your way while your trying to zip the shit up.... All while youve got an exhaust fan running like a raped ape trying to pull the doors into the tent.
 
hillbill

hillbill

Well-Known Member
My 7 year old Growlab has thos3 5 zippers also but the Zippers are straight and top and center have external flaps like the Big Ape Tent, design works and flaps help keep light out of tents. It replacement time is coming.
 
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