CMH vs latest LED tech

Bird_Dog · Jun 3, 2019

It seems that the general consensus over the last few years is that CMH beats LED in overall bud quality. However LED technology has been evolving quickly over this time - its interesting to read threads from 2012 and contrast that with the current state of LED growing.

With that in mind, for a new grow with quality as top priority, efficiency second and quantity third (though tied to efficiency), would you currently go with LEDs or CMH?

For my personal situation, looking at 5x5 growing space, 6.5' headroom max, cool temps generally. Comparing 2x320W HLG R-Spec vs 2x315W CMH. Happy to hear opinions!

Paddy

Rab.C · Jun 3, 2019

sounds like a great grow i have subbed

Jammal · Jun 3, 2019

I think currently the best tech for a 5x5 with quality as a top concern ,might be a 600w digi air cooled hps combined with 4 x 100w LED COBS,,,giving you a 1000w over a 5x5 but with the top efficiency's and better spread, great spectrum combo.

Bird_Dog · Jun 3, 2019

Jammal said:
I think currently the best tech for a 5x5 with quality as a top concern ,might be a 600w digi air cooled hps combined with 4 x 100w LED COBS,,,giving you a 1000w over a 5x5 but with the top efficiency's and better spread, great spectrum combo.

I was thinking of something similar with CMH. 1 315W and quantum 288s in each corner.

Sunshineinabag · Jun 3, 2019

Led and hps

Led and hps

I agree with everything said ....I used mag tech till I couldn't anymore.....I refuse to mess with capacitors I tech from 2008 that I have no real clue how to.properly change out.

Air kooltube and LEDs like these are my next flowering run with lambsbread I've been pollen chucking with

zachrockbadenof · Jun 3, 2019

my last '2' grows are with 2x315's (philip bulbs) in a 4x3.5ft tent - imo that is not enough light- if i can combat the heat in the upcoming winter, i will go back to a 1000w hps/mh-

Jammal · Jun 3, 2019

Bird_Dog said:
I was thinking of something similar with CMH. 1 315W and quantum 288s in each corner.

I don't think 1 315w CMH has the power to reach the outer edges of a 5x5, even though your going with bigger quantum boards. the blend of HID and LED won't be even.

Also a 600w HPS is far more efficient than CMH, the issue becomes because of HPS monochromatic light spectrum when running as a single light source, A 600w HPS when mixed with the LED COB CREE spectrum will be something totally different.

I also choose the 600w HPS and 100W COB combo for max light intensity and efficiency of respective technology's, CMH is still HID.

I'd be willing to put money on a 600w HPS & 4 x 100w cree LED COB combo being the ultimate 1000w combo for a 5x5 tent with current tech.

DemonTrich · Jun 3, 2019

Same room, same environment, same # of plants and strains, same everything

3x600hps (old)
And
4x 315 CMH (current)bsame yield. Less power consumption with cmh.
No rookie grower, dialed in like a mofo!

Bird_Dog · Jun 3, 2019

This is good info Jammal, thanks. I'm going to do some more reading on the 600W HPS as I hadn't really considered it initially.

Two considerations that factor in:
1. with a relatively low ceiling height and an affinity for sativas, heat is a bit of a concern with any option.
2. The basement stays fairly cool and I will be venting into the house as much as possible to take advantage of the extra heat. It's cold up here in northern Ontario! I have a chimney I can vent into when necessary, but most of the year we can benefit from some heat and humidity. Carbon filter will take care of the smell, and no neighbors to worry about.

DemonTrich · Jun 3, 2019

Do NOT vent into a chimney that also has your h2o heater or furnace using the same chimney spot.

Carbon monoxide is a KILLER!

Jammal · Jun 3, 2019

DemonTrich said:
Same room, same environment, same # of plants and strains, same everything

3x600hps (old)
And
4x 315 CMH (current)bsame yield. Less power consumption with cmh.
No rookie grower, dialed in like a mofo!

I think 4 x 315 CMH is a great option. Especially with the lower ceiling.

DemonTrich · Jun 3, 2019

Yes sir
I'm in a basement setting also. There are tricks to dialing in for cmh. A scrog/sog is best, as the penetration is only a bit better than led.

And x2 on premium Philip's bulbs only. And dont believe the BS of 20k and 30k hr bulb life. That's total bullsheet!

I still swap mine out 1x a yr.

Also, many t9 bulbs I've bought have broken spot welds. Inspect the bulb before firing.

Jammal · Jun 3, 2019

If money ain't no thing you could try 8-16 individual 100w Cree led COB units...

DemonTrich · Jun 3, 2019

I'm +1.3gpw with my cmh. I also went from 875 (aprox) monthly power bill to 500 tops. I swapped out 3000 (5x 600) hps/mh for 6x 315 Cmh. And couldnt be happier

Bird_Dog · Jun 3, 2019

DemonTrich said:
Do NOT vent into a chimney that also has your h2o heater or furnace using the same chimney spot.

Carbon monoxide is a KILLER!

Always a good reminder! Ours is tied into a sealed woodstove which only gets used in the winter, times at which the grow room vent will be venting into the house. Don't F around with CO!

Bird_Dog · Jun 3, 2019

DemonTrich said:
I'm +1.3gpw with my cmh. I also went from 875 (aprox) monthly power bill to 500 tops. I swapped out 3000 (5x 600) hps/mh for 6x 315 Cmh. And couldnt be happier

Jammal said:
If money ain't no thing you could try 8-16 individual 100w Cree led COB units...

Would the 100W Cree units have any advantage over the quantum boards? I wouldn't say money ain't no thing, but I don't mind an investment in quality.

TnTLabs · Jun 3, 2019

it all depends on your growing style, but yeah with limited height you might as well get the quantum boards and scrog

DemonTrich · Jun 3, 2019

I'm the last person to ask about led. I still believe they are garbage.

Bird_Dog · Jun 3, 2019

My worry with LED is the pace of advancement. I feel like if I wait 2 years the current tech will be old news, whereas CMH won't change much. This is based on nothing but my own notions...

Jammal · Jun 3, 2019

Bird_Dog said:
Would the 100W Cree units have any advantage over the quantum boards? I wouldn't say money ain't no thing, but I don't mind an investment in quality.

yes, the intensity of COB's over quantum Boards allows you to grow higher quality buds...if quality is top concern.

quantum boards would be easier and more efficient probably better yield per watt, But you will NOT get the same quality without the light intensity.

CMH vs latest LED tech

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