Ceramic Metal Halide (CMH)

[GreenThumb14]

My 250w retro white finally arrived today...

Highest temp on the bulb I measured was right near 500F, coolest was just below 200F. This is with the glass on the hood open and the vent fan off...

Weird thing is that this Accendo ballast hums... Doesn't get hot or really even warm to the touch but it hums. I only had it on for about 10min and it seemed to get a little quieter as the minutes rolled on but it still hummed away.



** Humming quiets down as the bulb warms up but hasn't completely stopped. Going to call Accendo tomorrow about it. The case gets pretty hot, hot enough to burn your hand. It takes a few hours to warm up to that level. I'm pretty certain the case is made of stainless steel, though... And with no cooling fan or fins, well that would explain the temperature. Accendo recommends in their installation instructions to mount the ballast on a hunk of aluminum. Other than that, I've seen no flickers or even color shifts. It's been running very consistent. The ballast starts the bulb up very slowly... Which I assume is like a "soft start" function.

 

[DrFever]

28 days with the CDMs. I'll try to get better pictures after lights out - I can't believe that I can get better pictures under leds/fluorescents than I can these, but..... They are so goddamn bright that I turned them down to 50% for these pictures and they were still washing out. Need more experience with it.

In the second picture, that bud is about 4" long. I think that the onset of flowering started a couple of days later with these than my hybrid fixture, but if this continues, it looks like the buds are going to be substantially bigger.

View Image

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any update should be what day 40 ???? get some pics up dude

 

[Bass Akwards]

SILVERHAZEFIEND:

Go ahead with the CMH. It's guaranteed to produce less heat, both around and beneath. In addition, it's a much longer lasting bulb, with a wider spectrum. Don't cheap-out on the ballast though, and keep it ventilated. The footprint isn't huge, but a bare bulb beneath a simple reflector with one small fan oscillating over the ballast, toward the plants, will work quite well. You always have the option of switching-out with a HPS bulb for the last few weeks, just to see how the strain(s) react.

 

[rives]

any update should be what day 40 ???? get some pics up dude

Sorry Doc, I'm falling down on the job! Actually, I've been taking pictures at 1 week intervals since flipping to 12/12, so these are from day 35. Although they have gotten much larger, it's hard to get a sense of scale and I was just going to wait until day 42, but here you go -

These lamps are a hell of a lot different than LEDs! I use V+B, and cut the feed back at day 28. The plants started losing color within just a few days, where with LEDs it would have taken several weeks. I think that the initial feed level should have been a bit higher, and the step-down more gradual.

*edit* I caught this one this morning just as the lights came on. This is kind of a medium-sized bud up front. Sorry, no left-handed tape measure!

 

[GreenThumb14]

Looking sweet, Rives. I'm loving the CMH and I'm glad that I stuck to my guns and didn't settle for MH/HPS.

 

[Azeotrope]

Under the 315w

 

[rives]

It looks like a little jungle in there, Azeo!

I am still having difficulty shooting a decent picture under these lamps - my white balance doesn't seem to correct out like it should and they are so damn bright that it also gives me trouble. The plants sure like them even if the Canon doesn't!

 

[Azeotrope]

I didn't spend a lot of time and energy on the photography and quite frankly, if I had it wouldn't be that much better! I really beat the heck out of these girls this time dialing in this new freezer set-up. The 315w bulbs do well. I'm sold......

 

[DrFever]

Azeo what kind of yields do you expect to get from 315 watts CMH ??? some girls under 96 watts second pic is one plant
not sure but how safe are these lights ???
Ceramic Metal Halides have a few downfalls, though they can certainly be used. As mentioned they don't come any bigger than 400w, so right away alot of growers would just pass them by. Secondly they won't run off an digital ballast, so there's no 'overdriving' of any sort. Perhaps the biggest reason they haven't really caught on is for safety reason, most bulbs blow on the inside...the pressure is released within the bulb. CMH however are infamous for blowing out seals, creating a hot torpedo of sorts There are also growers out there that would shy away from the UVB exposure associated with these bulbs, though I'm pretty sure one 26w UVB would produce more UVB than a 400w CMH.

 

[rives]

Doc, regarding the safety aspect of the CDM's, I don't think that there is enough data to come to a conclusion yet. The open-rated lamps are double-jacketed, and the single-jacketed lamps are only supposed to be used in an enclosed fixture.

 

[Azeotrope]

Dr. - This is a personal/medical and hobbiest activity for me. I don't know where you get your vibe, but your list of "downfalls" is laughable at best.

1) This bulb is running on a digital/electronic ballast and there are even more advanced options than the Philips OEM that it is on now. All of the options including the OEM offer much better output maintenance and life span than any HPS out there.
2) The bigger than 400w issue is only for those that feel they have to have bulbs bigger than 400w.... I used to run 3 x 400w CMH + 1 x 250w over a 4x6' area with 6 - NL5xHaze in coco and ran around 1.4 - 1.75g per watt without any real special efforts.
3) HPS lacks sufficient spectral coverage to optimize genetic potential and plant health. They are an old tech and if they are what floats your boat then great. Yield is not such a concern for me these days, but it is not as dependent on the light we choose as it is the whole set-up and process.

Lastly, I have witnessed your trolling through the defoliation thread and others. You run around here pounding your chest about nothing but yields and get in to boasting matches that are just childish. I mean coming in to the CMH thread and dumping on them is a little off. I have done it with the LED lovers for fun at times, but really, if you look around, many of them do well and I try to just make it a fun poke in the ribs.

I only wish the folks here at IC well. That includes you. I could go on and on about how only a fool would use HPS knowing what we know these days about photosynthesis and how plants use light, but I won't waste my time on it.

 

[Azeotrope]

Dr. - BTW - These were under CMH..... Do a room full of these and you can't complain....

 

[GreenThumb14]

I transplanted two auto ak47 a week after they started flowering from hydro to soil and put them under the 250w cmh and I'm surprised at how fast they recovered and started growing again... 2 days later they were growing an inch a day for 3 days before they stopped and are fattening up with bud sites now... Over 20 on the one.

 

[Fonzarelli]

CMH work EXTREMELY well for budding any strain of cannabis plant. I was surprised to see all of my strains reaching up to the light and fattening up real wide, encrusted with trichomes to the maximum.

The only thing that concerns me about CMH is the amount of yellow and green in relation to other wavelengths in the spectrum because I think it's possible for excessive yellow and green light to cause herm traits to come out in even the most stable of strains. Has any other growers seen this happening before with a CMH?

I read the part of this thread that was talking about switching from CMH to HPS and them thinking it was the UV drop that caused the herm, but I'm going to possibly disagree.

I bet the herm trait happened BECAUSE of using the CMH and it just came out in the final stages under the HPS. There is very little to none GREEN wavelengths in the HPS which mostly consists of ORANGE wavelengths.

It's just a thought and also an experience getting some crazy shit under the CMH WITHOUT switching to HPS or any other light source, so don't go jumping on me right away all you CMH lover, I AM ONE OF YOU GUYS LOL.

 

[Azeotrope]

Fonz - Green light is highly effective for photosynthesis and yellow has it's place as well..... I have been using these bulbs since they were first released and herms are a very, very rare occurance in my garden. Heck, I run like 80-90% females. I really think it is more a function of a genetic predisposition and the total environment.

It is true that a quick and abrupt change in spectral properties could stress a plant. If it has a heavy genetic predisposition, then I supose a shift might trigger certain plants. However, I have been playing with the difference between 4k and 3k CMH on and off for some time and even tossing in the occasional 8k halide with no herms in many grows....

 

[Azeotrope]

Let me expand in a simple way...... After CMH, HPS would possibly be one hell of a shock (letdown) for a plant. All that established plant chemistry and photosynthesis in action rolling on the nice full spectrum and then all of the sudden, monochromatic and not as nutrative HPS......

 

[Fonzarelli]

Just makes me wonder that if a particular strain has been grown/bred under HPS only lighting that if you were to just throw it under a CMH spectrum at any given time if this may contribute to gene expression in a not so good manner. After all, Hawaiians are happiest in Hawaii, Thai's are happiest in Thailand. If the spectrum is a certain way all through the strains previous generations, then it's gotta be at least possible that ANY changes whether we consider them good or bad could contribute to a plant sexing both ways maybe?

 

[JohnWayne]

Dr. - This is a personal/medical and hobbiest activity for me. I don't know where you get your vibe, but your list of "downfalls" is laughable at best.

1) This bulb is running on a digital/electronic ballast and there are even more advanced options than the Philips OEM that it is on now. All of the options including the OEM offer much better output maintenance and life span than any HPS out there.
2) The bigger than 400w issue is only for those that feel they have to have bulbs bigger than 400w.... I used to run 3 x 400w CMH + 1 x 250w over a 4x6' area with 6 - NL5xHaze in coco and ran around 1.4 - 1.75g per watt without any real special efforts.
3) HPS lacks sufficient spectral coverage to optimize genetic potential and plant health. They are an old tech and if they are what floats your boat then great. Yield is not such a concern for me these days, but it is not as dependent on the light we choose as it is the whole set-up and process.

Lastly, I have witnessed your trolling through the defoliation thread and others. You run around here pounding your chest about nothing but yields and get in to boasting matches that are just childish. I mean coming in to the CMH thread and dumping on them is a little off. I have done it with the LED lovers for fun at times, but really, if you look around, many of them do well and I try to just make it a fun poke in the ribs.

I only wish the folks here at IC well. That includes you. I could go on and on about how only a fool would use HPS knowing what we know these days about photosynthesis and how plants use light, but I won't waste my time on it.

Master grower.

 

[fungzyme]

Just makes me wonder that if a particular strain has been grown/bred under HPS only lighting that if you were to just throw it under a CMH spectrum at any given time if this may contribute to gene expression in a not so good manner. After all, Hawaiians are happiest in Hawaii, Thai's are happiest in Thailand. If the spectrum is a certain way all through the strains previous generations, then it's gotta be at least possible that ANY changes whether we consider them good or bad could contribute to a plant sexing both ways maybe?

Possibly, but that sounds like a huge amount of specialization for such a relatively short time frame - most commercial strains are what, maybe 20 generations away from the wild? And for them to have made enough changes that they not only respond best to the HPS spectrum but interpret a fuller more natural light spectrum as a stressor doesn't sound like the most likely explanation IMO.
Maybe in a lab where each generation's chloroplasts could be extracted and tested for their spectral response it could be done in short order, but breeders up to now have only been selecting easily identifiable characteristics (vigor, yield, resin, etc) and those gains could come from any, or a combination of several, genetic directions. They (or most of them, anyway) have also been introducing new genetic material at various stages in the breeding process, so a specialized trait like that would be 'watered down' regularly. And most expose their plants to MH lights during veg, so the same leaves will have been exposed to different spectra during their lifetime, just not at the same time, so that wouldn't lend itself to having a plant specialize in one particular bulb's spectrum.

Here's a fun Wikipedia fact about chloroplasts: they're only passed on from the female plant (except for some pines). I could see that
being useful some day when somebody identifies a female with either super-efficient or a higher number/cm2 of chloroplasts. Maybe Chimera's working on that in his secret underground laboratory.

 

[GreenThumb14]

Wish I could get this puppy in horizontal... http://www.ecat.lighting.philips.co...mps-with-allstart-technology/928601174701_na/