I've had a 400CMH since July '08. I'll have to look back and see when I added the 150hps. Not long after I'm sure. Maybe one grow.
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Well, the reasoning behind this is that a plant that grows faster (more red spectrum light) vs a plant that grows slower (less red spectrum light) will produce more vegetal mass, including bud sites.
I didn't say that red spectrum light in itself produces more bud sites than other wavelengths, but it's an interesting question.
I've never grown with CMH:s, but I have grown and do grow with Metal Halides, and there I also see a difference in bud appearance, similar to yours. Smaller but harder buds.
If you're using high quality bulbs that produce UV-B, they generally have an anti-UV coating, this is safety standard in the EU and I believe in the US/Canada as well.
It's often a titanium coating, similar to what you find in UV-protected sun glasses.
Crappy, Chinese-made bulbs may not have this coating, although in that case the box should carry UV-exposure risk warnings.
Which is why most Metal Halides put out insignificantly higher levels of UV-B.
stink.whistler
Member
The outer layer of the Philips lamps most people in this thread are using does attenuate the emission of UV, so some small amount may get through - but not much.
Bass Akwards
Member
Studies done many years ago ...
Studies done many years ago ...
The relationship between environmental stress and higher Cannabinoid levels was shown conclusively many years ago by the Midwestern researchers Haney and Kutscheid.
Stressors include soil composition, slope of the ground, direction of the slope, types of competing plants, and soil moisture.
http://www.springerlink.com/content/2112n1474q342243/
Studies done many years ago ...
The relationship between environmental stress and higher Cannabinoid levels was shown conclusively many years ago by the Midwestern researchers Haney and Kutscheid.
Stressors include soil composition, slope of the ground, direction of the slope, types of competing plants, and soil moisture.
http://www.springerlink.com/content/2112n1474q342243/
W
whiterasta
I am sure that some of these factors could be incorporated in an indoor situation but it remains that the indoor environment is a type of stressor of it's own and no information is available about just how this affects plant output. Outdoor factors are treated vastly different in an indoor setting. Things like temp variation are tolerated better outside as well as insect response and other variables which must be tightly contrlled for indoor success.
Also the effect on yield is not mentioned, however all of the stressors factored would seem to limit overall plant growth and therefore yield. I believe that this is an important factor in getting the fullest cannabinoid profile but I also believe that light spectrum is probably the most influential stress factor in an indoor grow.
For myself I prefer Outdoor fullness and heartier growth so CMH is a real addition to my micro climate as it seems to be putting the plant much closer to the look of the strain grown O/D.
Tight form and flowers, slightly more overall leaf but coresponding root mass also, More yield from 1600 CMH than 2K HS with less Popcorn and duff.
In use CMH is sweeter and more "hashy" than HPS but again slightly more leafy. It's primary use in chronic pain is vastly more potent in CMH plants suggesting a greater or fuller active profile.
In all I am very happy with my first two rounds with CMH. I am however going to ad back a 1K HPS with the CMH next round and see what I get then ,1.6K CMH +1K HPS covering 8x6.
Good info in here!
WR
Is this a CMH bulb? I was given this bulb 3 years ago when I bought my 400w magnetic ballast, . I ordered a MH conversion bulb with the unit and when it arrived, the MH conversion bulb was huge. I asked the dealer if they had anything in a smaller diameter. He sent me the bulb in the pic and let me keep the larger diameter MH conversion bulb.
If this is a CMH, would I be better running it for the flower cycle or should I switch to my HPS bulb?
If this is a CMH, would I be better running it for the flower cycle or should I switch to my HPS bulb?
Attachments
Hi whiterasta. Are you saying here that the buds are more potent with CMH for chronic pain relief?
Very interesting post too- I'll have to check out your grow thread.
W
whiterasta
Hi whiterasta. Are you saying here that the buds are more potent with CMH for chronic pain relief?
Very interesting post too- I'll have to check out your grow thread.
If you mean potent medically I have to say they seem so as for potent as in hit for hit comparison the best I can say is it tastes and feels much more "outdoor" than HPS. If you have grown your indoor outdoors then you will get what I mean. The CMH bud seems very outdoorsy, missing some of the overall greater cellulose thick stem traits but much closer to an outdoor plant than a lifelong HPS by an obvious margin.I veg under CFL so it may play into the less hearty stems as an outdoor plant and will indeed be trying a clone to flower CMH grow to see if it is even more of the same trend.
I am moving and am planning to doc. wiring and building the new digs along with some HPS vs CMH vs CMH+HPS comparisons of the same strain as they are growing. It is my own strain of ten plus yrs now and I am intimate with it's growth and effects so the change is quite obvious to me and I am sure you will see it too as I bring it all together.
WR
Bass Akwards
Member
Time & Space ... etc.
Time & Space ... etc.
Actually, there's a great deal of information on one specific point: Some strains just refuse to grow indoors. There aren't many outdoor specific strains on the market, but it would be interesting to try them with CMH bulbs just for the heck of it.
Many of the stress factors are easy to emulate indoors. Stick a chunk of 1 x 2 under a container of soil mix to tilt it away from the light. Let it wilt between waterings. Let it get root-bound. Keep the humidity low. Add that jolt of UV-B in the CMH bulb, and you're on the right track.
Side-by-side tests done on clones of several varieties in Holland that showed increased potency with UV supplementation. The graphs of cannabinoid levels are interesting.
Yield is lowered ... no doubt. That comes with the territory.
Aside from the strange spectrum of most HID lights, the biggest difference indoors is the lack of a breeze. We believe that Every grow can benefit at Every stage of growth, by adding two more oscillating fans.
Give us the outdoors any day ... . Even sea-level Minnesota Sativa will tastes better than Mountain hydro made with store-bought, "secret zombie hoo-doo juice".
Time & Space ... etc.
Actually, there's a great deal of information on one specific point: Some strains just refuse to grow indoors. There aren't many outdoor specific strains on the market, but it would be interesting to try them with CMH bulbs just for the heck of it.
Many of the stress factors are easy to emulate indoors. Stick a chunk of 1 x 2 under a container of soil mix to tilt it away from the light. Let it wilt between waterings. Let it get root-bound. Keep the humidity low. Add that jolt of UV-B in the CMH bulb, and you're on the right track.
Side-by-side tests done on clones of several varieties in Holland that showed increased potency with UV supplementation. The graphs of cannabinoid levels are interesting.
Yield is lowered ... no doubt. That comes with the territory.
Aside from the strange spectrum of most HID lights, the biggest difference indoors is the lack of a breeze. We believe that Every grow can benefit at Every stage of growth, by adding two more oscillating fans.
Give us the outdoors any day ... . Even sea-level Minnesota Sativa will tastes better than Mountain hydro made with store-bought, "secret zombie hoo-doo juice".
overmyhead
Member
FWIW, I just tried something, same cuts uder 400 w cmh in super sun 2 hood vs 600 w digital hps in cool tube, some other conditions may have been a little different 9dark time temps etc.) but the size and resin on the cmh ar much better, more dense. The only potential down side is that there is a little more leaf but it is all covered so it'll do the job for me. Not really into weighing anything atm and but I am pleased and will continue to use it! I would say that you pros might consider doing your traditional big lights but hanging some of these (250 or 400) vert to supplement a few hours a day - kinda create a high noon and increase the resin.
stink.whistler
Member
What brand of CMH bulb are you using that doesn't filter out the UV-B?
Bass Akwards
Member
Open fixture rated ...
Open fixture rated ...
Philips CDM400S51/HOR/4K/ALTO is the bulb you want.
Intended for industrial applications as a retro-fit of existing fixtures.
Philips also makes a line of CMH bulbs that filters out most the UV.
They're intended for retail uses where UV causes colors to fade.
Open fixture rated ...
Philips CDM400S51/HOR/4K/ALTO is the bulb you want.
Intended for industrial applications as a retro-fit of existing fixtures.
Philips also makes a line of CMH bulbs that filters out most the UV.
They're intended for retail uses where UV causes colors to fade.
Well I got a 400w CMH from the same place everyone else has, the order took a few days to process but I got it in like a week or less I think. 
Anyways, I'm going to be using the CMH for this grow until the plants start bud production, then I'll be putting the HPS in to finish it off with. I will definitely do a full run with it at some point, just not this time.
Thanks for all the great info in this thread!
Anyways, I'm going to be using the CMH for this grow until the plants start bud production, then I'll be putting the HPS in to finish it off with. I will definitely do a full run with it at some point, just not this time.
Thanks for all the great info in this thread!
C
coxswain
Just ordered 400W CMH. Can't wait to get it running.
C
coxswain
What reflector would best serve this CMH bulb for a 1x1m tent?
It appears to be a CMH bulb, but without the box I couldn't tell you for sure. (Look for the word Retrowhite.)
Using it for flower is really a judgement call. Some use it all the way through veg and flower. Some for veg and then HPS for flowering. Still, some use it for veg and HPS for most of the flower cycle and then CMH for the last two weeks or so.
I am about to start up my closet in the next week or two and am seriously thinking of using the CMH for veg and most of flower (to avoid a lot of stretch) and using HPS for the last two weeks or so to see if it will fatten up the buds any better. But, I am open to suggestions.
I did just that run before this one, and all HPS this run.
The nearly new HPS is going back in the box for a spare and maybe for next years cold grows.
I have no controls in place, and this is just seat of my pants...the CMH seems to make things frostier, fatter, and happier all around...which makes me happy all around.
Pics are much nicer as the bonus.
W
whatissixbynine
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stink.whistler
Member
I'm not sure that's true, I looked at the pdf on the advancedtech site and it said this:
WARNING: “These lamps can cause serious skin burn and eye inflammation from short wave
ultraviolet radiation if outer envelope of the lamp is broken or punctured. Do not use where people will remain for more than a few minutes unless adequate shielding or other safety precautions are used. Certain lamps that will automatically extinguish when the outer envelope is broken or punctured are commercially available.” This lamp complies with FDA radiation performance
standard 21 CFR subchapter J. (USA:21CFR 1040.30 Canada: SOR/ DORS/80-381).
From that standard:ultraviolet radiation if outer envelope of the lamp is broken or punctured. Do not use where people will remain for more than a few minutes unless adequate shielding or other safety precautions are used. Certain lamps that will automatically extinguish when the outer envelope is broken or punctured are commercially available.” This lamp complies with FDA radiation performance
standard 21 CFR subchapter J. (USA:21CFR 1040.30 Canada: SOR/ DORS/80-381).
(4)Outer envelope means the lamp element, usually glass, surrounding a high-pressure arc discharge tube, that, when intact, attenuates the emission of shortwave ultraviolet radiation.
Maybe there is another reason than UV for the frostyness? Or maybe just the bits that do get through are enough? It also may just be generic verbiage they put on all their lamps, since it seems it may also refer to non open rated lamps.
