CMH with LED

SmoochieBoochies

Well-Known Member
I have plenty of experience with CMH in growing tropical sativa or narrow leaf strains, but do not use LED. What do you need to know and I may be able to assist?
 

DesertPlants

Well-Known Member
I tested both out in a smaller area and found CMH way too hard on the eyes. A lot of people swear by them. After doing some testing, I would stick with COBs. LEDs run much cooler and you can customize the color range more. It's a personal preference and goal issue though.
 

SmoochieBoochies

Well-Known Member
The UV spectrum provided by the cmh is great for sats but not for our eyes so sunglasses in the grow room are a must. Hang out under them for too long doing lst and you'll get burned skin lol
 
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3GT

Well-Known Member
I'm using a Philips ballast + 3100k Philips bulb along with 16 bridgelux EB series strips @700ma (230w led +315w cmh) in a 2' x 4' wardrobe with 1 plant, long veg etc and the cmh led combo seems great so far! Its only my second grow ever keep in mind. I think the full spectrum from the cmh and canopy temps really complement the LEDs raw power?

The 315w is hung above and the strips light down the sides (she's 4' tall) buds all the way down have size/weight to them and in the middle where there's no strips the buds are tiny so it shows clearly the light is working :P

I think the ideal set up would be 4x4 single plant 3100k philips 315w up top, 400w 3k eb strips/f series strips on all 4 sides and 300w cobs up top (3k 90cri or maybe 1750k vero/2200k luxeon red meat) and I think that would smash out a biggun?
 

thccbdhealth

Well-Known Member
not the 3.1K but the 4.2K. with 3K citi 1212's @ 80 w per, 6 total.

plants love it. a few weeks to harvest for me.
Im running the 315cmh from Nanolux with the Philips 3100k bulb
Bulb is hung vertically.

Im currently talking with a builder and their current suggestions are 8 citizen 1212's but only running at 15w - i thought maybe 25w for 200w with the 315cmh.

Im in.a 4x4
and my cmh hood measures 18"x18"

Im also wondering about pattern spacing around the bulb?
24" square for center
or more to the outside edge
or 2u" square -closer to bulb for spectrum blend?

And color temp.
if hps is still best mixed with cmh wouldn't 2700k seam entreaging?

But i am running the same bulb threw veg and flower and that would leave me thinking 3500k or 3000k to veg under and then flower with both units on.

I do have a seperated propergation cabinet for clones and mothers that im thinking about 3 citizen 1212's in.
cabinet interior measures 32"w x 16"d x 44"t
Tent is 4x4 x 6'6"

I have been advised that ill need 24" for spetrum blend.
i have been running my cmh at 18" the last 2 rounds.

If i leave 24" between canopy and fixture and my fixture is 12" deep
Thats 36" and 12" of soil.
thats 48" of my 6'6" tent.
leaving 30" for plants before growing into that allotted 24"
18" off canopy leaves me 36".
my last round i didn't see any bleaching when some flowers were 13" down from hood height.
 

rkymtnman

Well-Known Member
Im currently talking with a builder and their current suggestions are 8 citizen 1212's but only running at 15w - i thought maybe 25w for 200w with the 315cmh.

Im in.a 4x4
and my cmh hood measures 18"x18"
i'm at 315w plus 480w of cob in a 3x4. some said this would be too much but my plants say it's just right.
 
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3GT

Well-Known Member
Im running the 315cmh from Nanolux with the Philips 3100k bulb
Bulb is hung vertically.

Im currently talking with a builder and their current suggestions are 8 citizen 1212's but only running at 15w - i thought maybe 25w for 200w with the 315cmh.

Im in.a 4x4
and my cmh hood measures 18"x18"

Im also wondering about pattern spacing around the bulb?
24" square for center
or more to the outside edge
or 2u" square -closer to bulb for spectrum blend?

And color temp.
if hps is still best mixed with cmh wouldn't 2700k seam entreaging?

But i am running the same bulb threw veg and flower and that would leave me thinking 3500k or 3000k to veg under and then flower with both units on.

I do have a seperated propergation cabinet for clones and mothers that im thinking about 3 citizen 1212's in.
cabinet interior measures 32"w x 16"d x 44"t
Tent is 4x4 x 6'6"

I have been advised that ill need 24" for spetrum blend.
i have been running my cmh at 18" the last 2 rounds.

If i leave 24" between canopy and fixture and my fixture is 12" deep
Thats 36" and 12" of soil.
thats 48" of my 6'6" tent.
leaving 30" for plants before growing into that allotted 24"
18" off canopy leaves me 36".
my last round i didn't see any bleaching when some flowers were 13" down from hood height.
Maybe try the Luxeon 2200k red meat cob? If you're not feeling those go 3000k 90cri citi1212/vero29/vero22/cxm22 etc

If you go 1750k vero or 2200k luxeon you could veg under the cmh? Or have 4-8 veg cobs in your 2200k array that are 4500k?
 

thccbdhealth

Well-Known Member
i'm at 315w plus 480w of cob in a 3x4. some said this would be too much but my plants say it's just right.
Thats what i was told when thinking about adding another 315 @ 4200k

But then i thought about led again, have been before i even bought the Nanolux.

Then with the led i could go red like hps,
@2700k or 1700
Or is it a better spectrum if i go 3000k or 3500k.
or even the 4000k
led but as if i was mixing the spectrum of both bulbs.

What about the spacing around the bulb
18"x18" cmh hood
20" square
24" square
36" square ???
 

rkymtnman

Well-Known Member
What about the spacing around the bulb
18"x18" cmh hood
20" square
24" square
36" square ???
my cmh is in a horizontal reflector, maybe 16 by 24? it's in the center of the 3x4

i built my cobs in a row of 3 so each one can be raised or lowered if needed.

my cobs are on 11/13 and the cmh comes on about 1 hour after the cobs and 1 hour before they go off.
 

thccbdhealth

Well-Known Member
not the 3.1K but the 4.2K. with 3K citi 1212's @ 80 w per, 6 total.

plants love it. a few weeks to harvest for me.
What driver are you running?
Your 6 @80w =480w
8 @60w =480w

Could I run that on the same driver?

Or should i be looking at the 8@80w
For 640w led and 315cmh for 955w
in a 4x4 x 6'6"
6" maxxfan 3 stage on max it's @420cfm.
 

thccbdhealth

Well-Known Member
Running the citizens 1212's @ 80w
Whats the efficiency like?
Am i better running a different chip since driving them so hard?
Or will i be just fine with the 1212's?
You seam to be.

Or now i should be looking at quantom boards if now thinking about this much wattage?

I just dont know.
 

rkymtnman

Well-Known Member
Whats the efficiency like?
no idea and to be honest it doesn't matter to me. the cpu coolers should keep them running way cooler than a passive heat sink

if you can do the DIY, i'd build cobs over the QB's. costs should be way lower.

so many decisions!!
 

thccbdhealth

Well-Known Member
Or should i just build it with a 200w driver.
do a test drive.
And then switch drivers should i want more light?
 
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