How good is Ceramic Metal Halide?

I've been reading about CMH lights for years! I'm familiar with all the "Industry Hype" and I know there are satisfied customers out there, because nobody really complaines about them. I'm playing around with the idea of designing a new grow area, featuring Ceramic Metal Halide lights, but now I'm having second thoughts! I just re-read a 37 page thread about how "CMH has them all beat!". Well, frankly, the argument wasn't that convincing.

I havn't actually used CMH lights yet, but I've always been under the impression that they are "God's gift to growers" - "Better in every way" - "More blue spectrum than MH, more red spectrum than HPS". Hell, what's not to like, they even run cooler! But then, I got to thinking - "If they're really that good, why aren't they the standard grow light, used by "everybody"?

On the "Graph" that everybody displays, they seem to radiate 3-4 times the amount of PAR light energy (across the whole "Growing" spectrum) compared to an "equal" HPS light. If that's true, shouldn't they produce 3-4 times the yield (or, at least, a significant imrovement - perhaps at least double!)? The more reshearch I do, the more it seems that CMH's aren't that much better then a good MH/HPS "Dual Spectrum" light, or mixed HPS's and MH's used "side-by-side".

The literature says "More blue spectrum than Metal Halide and more red spectrum than High Pressure Sodium", that tells me that they should perform better in both "Veg" and "Flower" stages - do they? I've read where they need a little help in the flowering stage - any truth to that?

The "temperature advantage" seems to be real, but it is only good for a couple of degrees, or so (every little bit helps!)! Maybe the real advantage of using Ceramic Metal Halide lights is the simplicity and cost advantage of only having one "type" of light do deal with. "White" light is more "User freindly", especially if it provides "UV-B" light for flowering. But the "bottom line" is performance! Do CMH's actually perform a lot better, or are they just nicer to use? I don't really want to hear "Claims and quotes" from manufacturers advertising campains. I want to hear from real owners and users!

So, here are my questions for you growers with some CMH experience:
1. Will CMH lights produce significantly more yield on a watt-to-watt basis with other HID's, or combinations of HID's (HPS & MH), or "Dual Spectrum" HID's (HPS & MH)?
2. Do CMH lights really outperform all other types of HID's in both "veg" and "Flower" stages?
3. Are the "real advantages" of CMH more a matter of convenience and cost, or more a matter of "Performance"?
Any responce to any question is welcome, as well as any comments anybody might have to add that might be of interest!

As far as I've heard they can be the best for a single bulb grow watt for watt. Although I don't think there would be that much of a difference between the best 600w cmh and a 600w HPS with a bit of exytra spectrum (like the hortilux super hps)
CMH do have to use CMH specific electronic ballasts though (as far as electronic/digital ballasts go (which can normally run both HPS and MH but not also CMH))
I've also heard of people getting skin burns from working on their plants under CMH bulbs even for a short amount of time, and that the reason these don't cause burns in industrial/work areas is because they are high up enough and far away enough from people that the UV rays or whatever don't hurt them. I don't know if that problem has been fixed lately, as I stopped researching them awhile ago.

Personally I would just get a good digital ballast that can run HPS and MH (I think they all can) and just run a MH for veg and an enhanced spectrum HPS for flower and avoid CMH all together (as it requires its own special digital ballast if you choose to use a digital, and these claims of people getting burnt)

They don't make 600w cmh. Most magnetic ballasts will work with the cmh, you don't need a special one. You might not yield even as much as a 400w hps. Cmh makes more trichs.

I've got a CMH on the way to experiment with. I'll post about it whenever it gets here. Also, as MAFIA said, CMH only go up to 400W at the moment and are designed to be used in MAGNETIC 400w hps ballasts (and there's also a 250W version avail.). They do make smaller CMH than 250w, and those have a completely different purpose/use altogether, like spot/flood lighting.

if your digital ballist like me look up sun pulse products, ill post a link hold on a sec....

HERE...http://www.sunpulselamps.com/

they go all they way to 1000 watts, and in kelvin ratings u wouldnt belief.

next harvest im trying to get one of the 400 watters in the 14K or maybe the 20K for late flowering! MMMMmmmmmmmm!

HERES the 400...http://www.sunpulselamps.com/index.php?page=shop.product_details&flypage=flypage.tpl&product_id=2&category_id=1&option=com_virtuemart&Itemid=5

mafia said:

- - - - Most magnetic ballasts will work with the cmh, you don't need a special one.

Click to expand...

That's an interesting statement, where do you come up with information like that?

I find that most CMH 250 and 400 watters are "Retro" (made to work with exsisting HPS ballasts), while most CMH bulbs below 250 watts call for dedicated CMH ballast or a "pulse start" MH ballast. I'm not saying they wont "function, to some degree" with a mismatched ballast - but I don't believe ANSI went to all the trouble of matching all those bulb requiremnets to all those ballast codes for nothing!

anyone know where i should be able to find one?? i need a 400w hor

websites or suggestions for possible stores in my area?

i called a couple electrical suppliers but nobody had them

am i gonna have to buy a case?

Everything I've read stated that the require a magnetic ballast designed for HPS lights, and even the ad for the CMH bulbs stated that.

Ok something was missed in these last few post, Going to restate afew things for posterity sake. First of all the CMH bulbs you are refering to at the beginning of the post are, I'm assuming, the Phillips brand which after all the discussion since we first started getting into these things around the forum has been decidedly the best available on the market for the time, but they offered 2 types of CHM that didn't need a pulse start balllast and that was the 250 watt and the 400 watt available as a "retro bulb" for the HPS peeps, and then the original that would work in old halide ballast no modifications nessecary. As time went on the retro had what we as growers really wanted so the info came out as "if you're going to try these get the retro CMH bulb from phillips and use the old ballast style." No those bulbs will not fire in an electronic ballast, they need the old core types; but much has happened since then, such as was just mentioned the sunpulse brand lamps and more intelligent chips being used in the E-ballast to recognize what bulbs they are firing, and finally an industry trying to get what the growers were asking for and get it to us quickly, which looks like that is now the case.

However the original question was about these older style CMH retro's and thats all I have for experience as of now. Here's what I've learned, this bulb kicks butt in comparison when I look at the final product with less watts being used (800 now) vs my 1000 watt hortilux eye (my original yield per palnt in a 5*7 room with hortilux was an average of 1 gram per watt to now an average 1.4 g/watt. There are multiple factors that could be adding to my results, for one now my lights can be closer to the plants not alot but when you talk lumens and the inverse squares law its enough; I now have two lights spread out over my canopy so I'm getting more efficient light spread than a single bulb could do anyways, but with the added bulb and ballast the heat in the room is now more of a burden and I have had to add a more vigorous fan and filter in to compensate for any additional heats of the extra ballast and bulb (soon the ballast will be remote but not yet, that will help I'm sure with the heats), I tried putting these bulbs into cool tubes and lost all the benefit of the extra spectrum so thats not a feasible option either. Yes I run 2 retro CMH's and nothing else so my newest lumatek sits and gathers dust while I use the oldest gear I have sitting around to run my lights. I also have 3rd 400 watt bulb that runs my veg and mother cab great thing about that is there is no drastic change in spectrum as my plants enter flower room so I get almost no stretch. Is there a drastic difference in yield no but then again I'm running 200 watts less and am I getting the same weight at harvest so maybe I should be saying yes. Overall what I like best is the beautiful frosting my plants are getting without the need for one more light, nice rock hard finished nugs, constantly healthier plants, and great tasting smoking/weed and I'm not paying upwards of a hundred dollars every six months to replace my bulb because of lumen decay and spectrum shift. This bulbs not the answer to everything but it is a nice all in one git'er did bulb that with a little playing around got me some outstanding results.

Hope that answered some of the confusion, now I'm off to go and get some of those sunpulse bulbs for my lumatek ballast cause they look nice but I'll never know until I try it myself, besides that I can't stand to see my gear sitting idle, I'll let you know what I find.

^Excellent response, worth a '+ rep', for sure. I run three 400 HPS and one 600 HPS in a 5' x 6' area, during the cold months, tyhen cut the light in half during the warmer months. Right now, I'm running one 600 and a 400, in a 3' x 6' area with a light rail moving them about a foot. I haven't got a harvest yet, and am only 2 weeks in, so I can't say what the results would be, but it looks good so far. Anyway, it's going to be tough to control the heat once it get's above 80* outside, even running air-cooled reflectors("Euro type" from HTG Supply)(I run open reflectors in the winter, with excellent results). So, I've been looking at 400 watt CMH bulbs, and am glad you posted some actual results. I might order some soon, and even if I don't get a nice increase in yield, I'll be happy to keep the temps down a couple degrees. Next winter, I'll probably have 4 of 'em running. Thanks man.

Got my CMH showing up tomorrow. Preliminary results concerning heat and light output to follow soon...