Ceramic Metal Halide (CMH)

[big ballin 88]

I think Simba said earlier in the thrad that Phillips holds the Rights to the 600w and 1k CMH. I want to see what happens, i think these lights are the future. Why use a HPS if you can get a more even spectrum with the same peak in red without all the extra bullshit.

 

[Sparky 6]

OK I'll ask- what happened to Simba anyway?

 

[SweetIndica2]

I think Simba said earlier in the thrad that Phillips holds the Rights to the 600w and 1k CMH. I want to see what happens, i think these lights are the future. Why use a HPS if you can get a more even spectrum with the same peak in red without all the extra bullshit.

Yea, i'm waiting for a 1000W Version. Right now i'm using a SolarMax Veg MH Conversion Bulb for Vegging and an Eye Hortilux Super HPS for flowering but it's so damn expensive to replace them. The bulbs together are about $170 or so at the cheapest and i really want to try a CMH. I bet a CMH 1000W would be killer, the penetration of a 1000W is already crazy even with just a normal MH or HPS, with a CMH you could get huge yields and huge colas i'm sure.

 

[hoosierdaddy]

I have seen some pretty convincing arguments by Simba. And I think he just may back up the use of a 400CMH coupled with a 400HPS over the use of a single 1000CMH or HPS.

I have been using a mixe spectrum of both CMH and HPS for over a year now, and I switched back to all HPS a grow or so ago. I have not gotten enough scientific info to make an educated decision, but from the seat of my pants, the mixed spectrum (400CMH+150HPS) does a much nicer job than all HPS. Seems to me that the plants waste a lot of enery when they go through the stretch that HPS seems to bring on. However, with the CMH the stretch is virtually non-existent. This may be a bad thing for some, but for me growing in a cab, I would rather have the buds working on growing fat, instead of growing stalk.

 

[HIGHGROOVE]

hello there interesting read about cmh......would those be good for vegging plants?

 

[Maj.Cottonmouth]

CMH is full spectrum so it is good for veg and flower, I am vegging under a 400w CMH and a 1000w HPS and I may switch on my second 400w CMH at flower.

 

[Sparky 6]

OK I'll ask- what happened to Simba anyway?

Anyone know this? Gettin kinda creepy.

 

[knna]

Anyone know this? Gettin kinda creepy.

I dont know anything about, but I know some people has a life out the forums. Sometimes it requires the time, thats all. Sure Simba will come back when he can.

 

[Sparky 6]

I dont know anything about, but I know some people has a life out the forums. Sometimes it requires the time, thats all. Sure Simba will come back when he can.

Kind of ironic that you say that considering he has over a thousand posts here. I was just checking to see if I missed anything important. Carry on.

 

[coxswain]

So advancedtechlighting.com is still ok? They ship to Europe?

 

[whatissixbynine]

.

 

[transplant]

Does any one know of a digi 400 watt used for a cmh? I know the hortilux bulbs are not made for digi also but many do as i do. so? any one??

 

[Rosy Cheeks]

I have seen some pretty convincing arguments by Simba. And I think he just may back up the use of a 400CMH coupled with a 400HPS over the use of a single 1000CMH or HPS.

I have been using a mixe spectrum of both CMH and HPS for over a year now, and I switched back to all HPS a grow or so ago. I have not gotten enough scientific info to make an educated decision, but from the seat of my pants, the mixed spectrum (400CMH+150HPS) does a much nicer job than all HPS. Seems to me that the plants waste a lot of enery when they go through the stretch that HPS seems to bring on. However, with the CMH the stretch is virtually non-existent. This may be a bad thing for some, but for me growing in a cab, I would rather have the buds working on growing fat, instead of growing stalk.

Is the stretch your only criteria for CMH+HPS is doing a "much nicer job" than all HPS? How about quality, yield and flowering times?
Stretch isn't really a problem (depending on genetics), there are many ways of dealing with it.

Plants do not "waste" more energy while growing under High Pressure Sodium light. Let me explain to you how it works. Different light spectrums affect plant growth differently. Red spectrum light makes you plants grow faster than other types of light spectrums (violet/blue coming in on a close second, green spectrum coming in last), because chlorophyll - the main pigment in the leaves - absorb the red light, while carotenoids absorb blue-green light (green light is not effectively absorbed by photosynthetic pigments). Red light is the most effective in photosynthesis because it has exactly the right wavelenght to excite chlorophyll electrons and boost them out of their orbits to a higher energy level.

With other words, 'red spectrum' lights such as HPS make your plants grow faster.
Now, this can be both good and bad, depending on how you grow. Good because red spectrum light produces 'more' plant (and therefore more bud), bad because increased growth also means larger internode space,
It is not the same thing as 'stretch'. Stretch, or Etiolation, is the growth of stem tissue in total darkness. Absence of light makes starch levels drop, strengthening tissues and fibers begin to soften, cell wall thickness decreases, vascular tissue is diminished, auxin levels rise, and undifferentiated tissue begins to form. Therefore stalks stretch, due to shaving off 6 hours of light per cycle when you flip from 18/6 to 12/12.

So it's evident that if you hit your plants with primarily red spectrum light in the first two weeks after switching to 12/12, you will have difficulties keeping the internodes short.

Better then to hit them with mainly blue light during the stretch, and increase the red spectrum light as the bud sites starts to develop.

 

[hoosierdaddy]

Are you asking about my experience or teaching me? ...lol


So, you feel that there is no difference in energy spent during the "stretch" period if the stalks are doing the majority of the growing, and you feel this is due to them only growing at night? Got references, or is this your take?

I think there may be some studies that show mixed spectrum is far better than a separation of the two. I know that there is some diff in the sun's UV output with seasons, but the diffusion of the light and the growing spectrum seen is virtually the same throughout the season.

I think ATL is still recommending a combination of the two types of artificial spectrum, but as far as if they are talking about mixing thourghtout or seperating the mixing I don't know. I do know that Simba has stated his thoughts, and I think he said something like he would use the CMH, then HPS, and then the CMH.

I am almost convinced that resin production is better when CMH is involved, but like I have stated, I nearly no controls in place. I see no difference in finish times of clones.

 

[Rosy Cheeks]

No, I'm not teaching you,

I know you're an accomplished grower, but there are lots of people around who haven't got the hang of it yet so I tried to put the whole context in so that it makes sense.

No, It's not what I said. Red spectrum light boosts the photosynthesis, faster growth means larger internodes. That in combination with etiolation makes for a meaner stretch. But it's not a "waste" in per se, you do produce more elongated stalks (which can be reduced) but also more bud sites. And eventually, more bud.

I agree with you that mixed spectrum grows better plants, that was never in question. Personally I use mostly HPS bulbs with reinforced blue spectrum, and I veg with blue light neons. The HPS shows its worth in mid and late flower, but I'm sure you can run CMH instead and get top results with. Sunlight is full spectrum light, and even though some wavelengths seems to do little for growth, they're all valuable for the plant.

My question to you was if you think CMH:s give a better overall end product than HPS grown bud. As far as I know, there is no proven way to increase resin production, apart from keeping the plant healthy and thereby optimizing its capacity to produce resin.

Could be that a more varied light spectrum does just that.

 

[indifferent]

Blue light neons? what are those?

There is a way to increase resin - stress, some forms of stress will produce more resin, but at the detriment of yield. Salicylic acid is said to trigger the stress response and may have a resin increasing effect. Two products I have found that do increase resin levels are AN Hammerhead and Atami Bloombastic. What constituent in those that is responsible I don't know. I've noticed different PK boosters can give different levels of resin, the differences are never large, but definitely there. For instance, Atami PK13-14 always produced slightly less resin for me than Canna PK13-14 .

The more important thing imho is the amount of THC within the resin present, THC production can be stimulated by UVB light but the precise method for doing this hasn't been worked out, the studies used irradiances between 1 and 4 hours during the middle of the day which is when UV levels are highest in nature.

 

[Rosy Cheeks]

Just the way I express myself. Blue light neons as in neons high in the blue light spectrum. The light is cold white to the eye.

There has always been speculation on how stress induction could produce more resin or more potent resin (the old "run a nail through the stem" trick comes to mind), I just haven't come across a scientifically performed research study where it is established that it is so.

Salicylic acid is a plant molecule that works as an activator of the plant's defense system against pathogens, it also promotes DNA-binding proteins that initiate new protein synthesis.

Whether its plant defense system boosting effects increase resin production or not I don't know, I know it's rumored to do so on certain Canna cultivation web sites.

If there was a direct relation between the plant's natural defense against pathogens and resin/THC production, then you could perhaps argue that the strains that are the most resistant against fungi, mildew and pest attacks are also the most resinous and potent. I've never come across any indications that it is so. In fact, one of my most potent plants is the Blockhead, and it's crap against pathogens and pests, doesn't stand up against them at all.

On the subject of Advanced Nutrient products, Scorpion Juice contains Salicylic acid. Nevertheless, AN's own research does not seem to show that Salicylic acid increases resin production. If it did, I'm sure AN would not fail to point it out in their aggressive marketing. Scorpion Juice is marketed only as a natural defense 'strengthener'.

But who knows, there's still lots to learn about plant chemistry.

 

[Sparky 6]

It's difficult to find a decent test grow pitting HPS vs CMH- I've never seen one done to my satisfaction. I've seen some with different wattages competing, one that was supposed to be virtually identical but the grower made major changes to his grow room between compared grows adding a lot of reflection etc, and I saw one where the ability of the CMH light to be placed closer to the plants than other HID lights was not taken advantage of. Proper test parameters are specific and unusual for this light IMO.

 

[hoosierdaddy]

With having a 150HPS directly below the 400CMH in my vertical tube, it really only benefits the lower part of the plants. It helps to keep good light down there and what would be much smaller popcorn, gets about as developed as a 150 can get them.
It is the top of my plants that see the most CMH.

As far as the plant seeing different growth rates due to differing spectrum, that is easily seen. But as far as there being more bud sites created during an HPS stretch as opposed to the CMH stretch, I don't buy that at all. I have not seen any sort of evidence that this would be the case. I see different space between nodes, not more or less of them.

I do see a difference in the appearance of the buds, in that they will appear to be leafier than same clone in HPS, however, I think the bud is in fact a bit more leafy, but it also seems to carry more calyx weight.

I am pretty sure the CMH has a good bit of UV working, and I think I see it's effects first hand from the heavy discoloring of the stalks and buds. Stalks that see the CMH light during their life will normally be a very dark rich purple color, and only green where the shadows are cast.
Some have stated that having the bulbs in glass tubes will cut down any UV present, but I have them in cheap lead glass...and I have also seen where the lead content of cheap mexican glass can actually help to refract the light better at the unseen levels.

 

[Sparky 6]

Interesting strategy hoosier. Sounds like the HPS would make the lower branches grow faster so that they could get to the CMH, promoting a bushier plant. How long have you been growing like that?