Ceramic Metal Halide or Light Emitting Ceramic, CMH/LEC

Umpty Candy

In Bloom
Let´s talk about them here, ok amigos.

Read and heard a great deal of good things. How does the heat compare to others? Any experience on running CMH vertically? Does the CMH spectrum affect taste etc? Does 315W equal 400W HPS? How bout 630W, can on use it instead of 1000w HPS and get similar results? Light penetration must be the same, no?

df
 

spyralout

🌱🌿🌲🔥💨
Staff member
From all things I've read and experienced (315 W CMH):

- 315W CMH is just about equivalent to 500 W HPS (not quite 600 W)
- Heat is considerably less than 600 W HPS (about a little less than half)
- Typically CMH are better vertical vs horizontal. Vertical hoods are expensive. I've tried horizontal 600 W HPS hood w Mogul socket converter and bare bulb vertical. The horizontal seemed to concentrate light on one very specific area while the bare bulb was a night light glow, which I ended up going with after trying the two. I couldn't justify buying a big vertical hood for space reasons.
- All buds that had the closer exposure to the CMH had rock hard, fuzzy trich buds. The first buds to be smoked were the CMH exposed buds, by all parties involved. There's just something about that spectrum/bulb. In a CMH/LED combo, the buds get really frosty and solid. CMH/HPS combo was a close second, but the heat generated likely slowed things down a bit.
- I've read that two 315 w CMH is better than a single 630 W cuz you can spread the light out more and it doesn't get as hot
- IMO CMH is a good "more than supplemental light" as I've tried just a plain CMH run on a few plants and they didn't seem to be nearly as good as a CMH combined with other type of light.
 
CMH beat standard MH & HPS in CRI (color rendering index), efficacy (lumens/W of input), and they have greater lifespan than both. They also emit UV-B which has 'anecdotal approval' (if you will) from many growers, but is also largely nullified with thick glass hoods meant for keeping heat manageable. Their overall increased efficiency means a more manageable thermal setup, which can mean a big difference in cooling costs, and happy plants with cool leaves tend to grow well.
And CMH can be run thru the entire grow as well. No need for switching bulbs and ballasts out if you only have one tent. I believe there may be a couple spectrum options with CMH, mid 3000's and low 4000's I believe, but not sure about that, so don't quote me on that.


I don't know however if the advantages CMH holds are enough to make up the difference in raw 'horsepower' a 1000W HPS or MH has over a 630W CMH, but definitely, if you put them up against eachother watt for watt at a 1:1 ratio, then CMH should destroy them both assuming all other things (medium, temps/humidity, feed schedule etc) being equal.

And I can't speak on vertical vs horizontal, all my friends that use them all use horizontal setups, so nothing to compare, so I'd just be talking shit otherwise lol.

MH & HPS are industrial lighting designed back in the 50's and 60's, meant for street lamps and factory floors. Neither were initially intended for indoor horticulture.

CMH were perfected for wide spread use in the mid 80's or 90's I believe, with film and television, photography, and other industries in mind that required a more accurate daylight spectrum. Luckily for growers, plants have evolved demanding virtually their exact color spectrum, so even if it was not the original intention, CMH goes hand in hand with indoor growing.

If for whatever reason I couldn't use my LEDs, and I had to choose a HID setup, it would be CMH. I've even thought of supplementing with them, but I'm out of room on my electrical panels at this point lol. My circuits are so overloaded, in fact, I might not even be able to charge this pho....
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(Lol)
 

Orion

In Bloom
I have been using CMH 315's in my hunting room for awhile now in the same Sun system 2 hoods without glass that I rocked 600 HPS with for years and I have a bunch of positive results and would never go back to 600HPS ... never looked into LEC...
 

Amarok

bad mother chucker
I have been using CMH 315's in my hunting room for awhile now in the same Sun system 2 hoods without glass that I rocked 600 HPS with for years and I have a bunch of positive results and would never go back to 600HPS ... never looked into LEC...
CMH and LEC are actually the same thing. Ceramic Metal Halide and Light Emitting Ceramic, iirc. One may be a brand name.

Edit after verification:
The term "Light Emitting Ceramic" or "LEC" is sometimes improperly used to describe ceramic discharge metal-halide grow lights in general, though that term is actually the registered trademark of a specific brand of ceramic discharge metal halide light.
 

Jewels

Tilts at Tables
Whilst there will always be appealing reasons to be on the recent end of technology,,,,

Last time I had a fixture go down, I bagged the biggest handfull of buds I could grip, and cold traded them for a 1k HPS ballast - before the sun went down.

,,,,As there will always be appealing reasons to be on the trailing end of technology.
 

Orion

In Bloom
@Agent Trent Hauser ...lol...maybe that's why I never looked up LEC lights...

My CMH bulbs hit 90% right at 2 years of 12/12...SAVINGS....My terps and overal profile is really more like outdoor than anything I can ever remember growing except some texada timewarp...it loved HPS for whatever reason grew really good indoors for me...never grew it with CMH though...
 

Amarok

bad mother chucker
My CMH bulbs hit 90% right at 2 years of 12/12
That has been one of my questions about these, how often do the bulbs need to replaced?

90% after 2 years of 12/12 is definitely acceptable to me.

Can you (or anyone) speak to the difference between something like the Phillips bulbs vs the cheaper ones? At my local shop the Phillips are $100 vs $80 for the generic. I have no problem paying extra if the performance is there, but don't want to just be paying for a name.
 

Orion

In Bloom
That has been one of my questions about these, how often do the bulbs need to replaced?

90% after 2 years of 12/12 is definitely acceptable to me.

Can you (or anyone) speak to the difference between something like the Phillips bulbs vs the cheaper ones? At my local shop the Phillips are $100 vs $80 for the generic. I have no problem paying extra if the performance is there, but don't want to just be paying for a name.
I only have used Phillips...if it ain't broke....I can get you those bulbs for like $79 thru Grow Generation my commercial account...
 

Amarok

bad mother chucker
I can get you those bulbs for like $79 thru Grow Generation my commercial account...
I just noticed this edit. Thank you so much for the offer. (y)(y):flame:

There are few things one can do that are more kind than helping a stranger for no gain.

I don't think I would ever trouble you for the sake of $20, but just reading the offer made me happy and grateful

Thank you again. Interacting with good people always makes me smile.
 
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