Ceramic Metal Halide (CMH)

[simba]

they may sound bad to some but its for our benifit..

if yall noticed life light usto sell the philips CMH (labeled as there own bulb ya right) at 109 then 90 then 70 during that time a they also had a Chinese copy sold at 70-60 (and was a major patant infrigment of philips Open Fixture Saftey device IE the Paper clip wraped around the arc tube.. then they brought out the GE mentioned above yet gave no MFR detail on ge phlips or china copy. .. and sold for a prety penny.. now they say who the mfr is cause they look real bad by hiding it when customers find out they been Had..
if you watched there price drop and when the china and ge versions where introduced it was cause they couldn't make as much $ off philips CMH.. not that they where truely better..
I have played with them all and seen results and i stick with philips CMH and as you can see not as profitable as GE or china copy. so that says something.. IE i dont promote CRAP>> LOL..

CRI>> we had worked with a sulfur lamp that had a 98-100CRI but it would be horible for us .... Way to much BLUE to red ratios.. (and 70%+ of its total energy is outright wasted on plants)

(basically marketing games to profit off the customer not give customer best benefit)
i started with philips CMH 4k and never switched to more profitable lamps..

 

[VirginHarvester]

Simba,

I've read every page on this thread over the past month and it's really informative and fun.

Pretend I'm growing an eight week strain. It seems to me CMH is best at least for vegging and the first couple weeks of flower, with maybe HPS the middle four weeks of flower, then the final week or so back to CMH in order to produce the resin potency(UV).

1) So is it a good idea, or unnecessary to want to use an HPS during part of the flower period to produce tighter, less leafy buds?

2) Even as a supporter of CMH would you see that as a good compromise to produce the best or is it just proving to be unnecessary for HPS as CMH produces the best possible growth pattern the entire way?

One reason I ask this is most complete grow kits come with a decent red spectrum HPS anyway. Some people in your thread have debated HPS vs CMH for producing better overall bud structure and maybe they have a point. One downside with HPS seems to be that the plants would want to stretch a lot more during flower. I have limited height in my space so stretch is an issue but at the same time don't want to produce a B grade produce if some weeks of HPS would make it a strong A grade. I'm also wondering if it might be ideal to alternate between CMH and HPS, or even use a CMH and HPS together in a dual lamp environment so that I could veg with a 250w CMH and add a 250w HPS during flower to increase the reds and maybe produce the tighter, less leafy buds and still have the UVB thanks to the CMH. I realize in a dual lamp I would need an extra ballast. The other idea here is that I have redundancy so that if one bulb or ballast goes, I have the system still running. So I'm just thinking and wondering if some combination of alternating between CMH and HPS during, or running the CMH and HPS together most of flower might be the best overall.

3) Are HPS bulbs protected like CMH so that I wouldn't have to use a glass hood? Or, if they are not protected and glass hood is required, do most hoods have removable glass?

4) If I had a hood and the glass was not removable what percentage of UVB CMH produces is filtered out by the glass?

Thanks.

VH

 

[knna]

BTW - question for Simba on the spectragraphs . On the left side column labeled relative energy , what unit of measurement is being used ? microwatts/cm2 hopefully ?

uW/cm2 is a unit of irradiance, thus related to the lighted surface, not to the light source. It varies a lot depending on where you take the measurement. Thats the useful figure, on the other hand, on your own setup, but you need to measure it at the top of the plants (you can use a luxometer and convert it to uE/m2 using the PPF/Klm ratio of the sheet i linked).

Spectrographs are expressed on mW/5nm (/Klm): mW emited on each 5nm waveband for each 1000lm. Thats the scale often used by Phillips. Sometimes you see it as uW/5nm/lm, but its exactly the same (mW are 1000 uW and Klm are 1000lm). The waveband used varies too, some graphs use 1, 2 and 10nm wavebands instead of 5nm.

Notice that spectroghraps are a image of bulb's radiance, an absolute measurement of how much energy it emits per second. To perform that measurement is required an integrating sphere.

Anyway, vertical scale of spectrographs is of little uselfuness. What's important is the relative relationship between the different wavebands. And relative ratios are undependent of scale used, as far all the graph uses the same scale.

3) Are HPS bulbs protected like CMH so that I wouldn't have to use a glass hood? Or, if they are not protected and glass hood is required, do most hoods have removable glass?

Most HPSs are rated to work in open fixtures. The problem is with MHs, wich sometimes cracks so its required an enclosed fixture to avoid poisinous material falling off. But with moderns CMHs that problem is way less common than before (its easier to win the lottery ), thus some of them are already rated to work on open fixtures.

4) If I had a hood and the glass was not removable what percentage of UVB CMH produces is filtered out by the glass?

Most glasses filter almost all UVBs rays. In fact, most CMH have a UVB filtering glass envelope so they emits very low UVB. With another glass layer, UBV reaching plants is negligible.

While UVA are filtered just partially, UVB are filtered almost completelly.

It would be nice if somebody with a spectrograph may measure actual UVB irradiances at plants. But i bet it is going to be from very low to almost not measurable (nothing) (depending if there is another glass layer between bulb and plants).

 

[trichburner]

(you can use a luxometer and convert it to uE/m2 using the PPF/Klm ratio of the sheet i linked).

I can't view the zipped XML files in the link . Is there anything in those files that isn't shown or explained in the corresponding threads ?

uW/cm2 is a unit of irradiance, thus related to the lighted surface, not to the light source. It varies a lot depending on where you take the measurement. Thats the useful figure, on the other hand, on your own setup, but you need to measure it at the top of the plants

Spectrographs are expressed on mW/5nm (/Klm): mW emited on each 5nm waveband for each 1000lm. Thats the scale often used by Phillips. Sometimes you see it as uW/5nm/lm, but its exactly the same (mW are 1000 uW and Klm are 1000lm). The waveband used varies too, some graphs use 1, 2 and 10nm wavebands instead of 5nm.

Notice that spectroghraps are a image of bulb's radiance, an absolute measurement of how much energy it emits per second. To perform that measurement is required an integrating sphere.

Anyway, vertical scale of spectrographs is of little uselfuness. What's important is the relative relationship between the different wavebands. And relative ratios are undependent of scale used, as far all the graph uses the same scale.

Thanks for the clarification .

 

[VirginHarvester]

Most glasses filter almost all UVBs rays. In fact, most CMH have a UVB filtering glass envelope so they emits very low UVB. With another glass layer, UBV reaching plants is negligible.

While UVA are filtered just partially, UVB are filtered almost completelly.

So you believe the proposed UVB benefit of producing THC even with an open hood is not that great with CMH?

Would it be ok to use an open fixture with CMH or HPS provided cooling was adequate and does an air cooled hood usually imply closed fixture because that's how an air cooled hood has to be?

I'm just trying to figure out what the options are with hoods- if you could use a CMH open fixture then if you switch to HPS slide glass back in and use air cooled fan. Thinking air cooling not as big an issue with CMH but definitely would be with most HPS configurations especially if for some reason I was then using both CMH and HPS in a dual lamp. And, trying to understand if an air cooled lamp still works just fine without glass(open fixture).

Would be disappointed if CMH doesn't appreciably improve resin quality because it seems like along with having less stretching in veg and flowe it's the other key benefit of CMH.

I have seen a graph someone made of his using a configuration of UVB lamps focused on part of his canopy last couple weeks of flowering and he showed pictures and graphed the crystal production of the areas with and without the UVB. It was significant. But, this was with UVB bulbs and there really are no adjunct UVB bulb configurations set up for grow rooms. He had to design this on his own and I don't think I could or have space so was hoping CMH was significant source of UVB.

 

[simba]

as far as the hps retro whites and all cmh Protected lamps.. the uv is minimal at best.. no one will deny..
however the full spd kinda IMPHO makes up for it and the little that is there is hitting plant (if you dont have Lots of room or extra thick glass or quartz glass plate in reflector)
ya knna i was working on uvb when it was asked last time but it wasn't pushed so it got pushed off the burners persay..
however when you think about how far your plants are from the lamp vs philips or other companies saying no uv i truly think they are thinking min distance at like 10 feet for 250 and 15-20 feet for 400 watter..
I could be wrong..

as far as adding hps supplementing during flower.. i haven't had any solid reports and within that how many watts of hps per watts of cmh and what bulb.. when to use or switch for a time.. etc.. so i have not really recommended any thing..
ill say i personally use only cmh in all grows good and GOOD>> with no supplementing and my 400 cmhs are fixed at 36" open bat wing (im to dam cheap to keep good hoods.up till im 100% leak fixed.. (i had a water leak and hoods i just put up SS1V1 where getting wet.. and i didn't want them to rust or cake the paint.)

90% of hps lamps are Open fixture rated..
the reason being hps arc tube isnt as high pressure internally as MH or even CMH.. (cmh has higher internal presure than MH. From what i remember ill see if pdfs have any thing on exact, I saw it somewhere.)

and mh and cmh burn hotter (arc tube hot as 1000c) and cmh arc tube will hold heat even longer than MH qaurtz arc tube. that cools fast.. )cmh can start fire at double the distance of mh.. Thus Open Fixture CMH and MH are a MUST>>
400 ge cmh blowing in a open fixture.. Forget the boys in blue coming your going to a trauma 1 center LOL
it would be like a 1kw mh going..

uW/cm2 is a unit of irradiance, thus related to the lighted surface, not to the light source. It varies a lot depending on where you take the measurement. Thats the useful figure, on the other hand, on your own setup, but you need to measure it at the top of the plants (you can use a luxometer and convert it to uE/m2 using the PPF/Klm ratio of the sheet i linked).

Spectrographs are expressed on mW/5nm (/Klm): mW emited on each 5nm waveband for each 1000lm. Thats the scale often used by Phillips. Sometimes you see it as uW/5nm/lm, but its exactly the same (mW are 1000 uW and Klm are 1000lm). The waveband used varies too, some graphs use 1, 2 and 10nm wavebands instead of 5nm.

Note i said.
Ill go back to the email.

as far as the relative i have been asking for the exact rating since i started moving them.. and still only saying that it is Mw/cm2 (that is from the Lead Philips CMH Engineer) (that was said after we said we needed something or we cant go any further..)
so dont hold me to it but im holding them to it..
i did have a partner with an actual spectrograph thingy.. but wont hand over results unless we pay allot more.. Piss off. ill buy a unit for what he wants to test just the hps retro whites. i have many i want to test. accurately.... (note the unit will not measure total outputed rather the actual radiation per nm range..

(i should say was partner in combining tools to cut overhead costs.. IE test measurement and testing lamps out He does RD ligthing.. Didnt work out)


ya i was quoted a Spectrograph from Intl Light about a year ago and i cant justify the cost vs the return. (i dont remember exactly but the two charts from the philips PDF to the cmh tested to be wanting to find the exact difference IE if there was a major dif then i would have jumped on philips if that makes sense..

i will say adding a reptile bulb towards end of harvest is not a bad thing.. just dont go overboard.. UVB from what we know /think. is that the uvb causes the plant to fill the glands with THC goodness not make more of the glands. IE dam forgot there name...

 

[VirginHarvester]

My last two grows were outside so the complete mechanics and risks of growing inside are still a bit of a mystery so I'm going to ask for your help answering some other questions I have and that just occurred to me from your last answers. I'm going to number the questions just so you have a better chance of catching them all. Appreciate in advance all your help.

as far as the hps retro whites and all cmh Protected lamps.. the uv is minimal at best.. no one will deny..however the full spd kinda IMPHO makes up for it

I thought a healthy amount of UVB was one of the key benefits of CMH. So now I'm having a hard time seeing the benefit of CMH unless stretch becomes a huge issue over a longer flowering strain in 6 feet of vertical grow space- indica and indica hybrids should do just fine in that space. Nothing against CMH, I was just under the impression the amount of UVB was more than minimal from reading the thread and would have guessed 20-25% of what the sun gives off. But that of course was just my impression, not that anyone actually stated that number.

ill say i personally use only cmh in all grows good and GOOD>> with no supplementing and my 400 cmhs

1) Before CMH did you have a lot of experience with HPS during flower period and notice any difference in the quality of buds when you switched to CMH- more leafy, less compact?

and mh and cmh burn hotter (arc tube hot as 1000c) and cmh arc tube will hold heat even longer than MH qaurtz arc tube. that cools fast.. )cmh can start fire at double the distance of mh.. Thus Open Fixture CMH and MH are a MUST>>

I'm confused. So CMH is hotter than HPS. I was under the impression MH was hottest followed by HPS, with CMH being cool enough that a cooled hood was often not needed. 2) So based on the way I'm reading this if I didn't need an air cooled hood for CMH I wouldn't for HPS either. Is that right?

Grow space- right now it looks like my grow space will be a closed off closet of 30 x 30 x 60H. All I really care about is having up to four shorter indica type plants flowering at a time or occasionally one or two sativas LST'd and bent over some to manage space. 3) Is 250W CMH plenty for that space or slightly "under powered"?

What you wrote about CMH starting fire scares me. 4) But if CMH and MH burn so hot, why would open fixture be a must? It seem like closed fixture would be required for heat management(air cooled) and protection in case they do explode. And I guess air cooled hoods are still an option even if the hood is open, no glass.

400 ge cmh blowing in a open fixture.. Forget the boys in blue coming your going to a trauma 1 center

5) How often do CMH's, or any bulb blow up? I would guess not to often as I had not heard of it so far in the thread.

6) It's only really dangerous if it happens while you're there in front of it, right?

7) How likely is an even like that to start a fire and if they do blow and lets say you were not home does a ballast usually know to shut itself down?

8) What are the kinds of things that cause them to blow?

9) I thought I read one of the things needed to be done to maintain these bulbs(all bulbs) and keep them from blowing is to keep em clean. Where could I read more about how to maintain the bulbs, especially techniques and handling instructions to make sure I don't cause one to become unstable?

i will say adding a reptile bulb towards end of harvest is not a bad thing.. just dont go overboard.. UVB from what we know /think. is that the uvb causes the plant to fill the glands with THC goodness not make more of the glands. IE dam forgot there name...

10) But for instance with a four plant grow one reptile bulb isn't likely to spread UVB around the grow space or very deep in the canopy is it? Even those are pretty much only good for a couple feet and not a very broad dispersion of light? Then I think from what little I've read about them you have to time them on and off for only a few hours a day and manage additional heat on plants.

 

[trichburner]

VirginHarvester , keep in mind that there is no conclusive evidence that UVB is responsible for the enhanced effects of cannabis from tropical regions . Genetics , heat , humidity , soil composition , environmental stress , human selection or a combination of all the above plays just as much as a factor (probably more of a factor) than UVB . The cannabis imports to america in the 60's-70's was from regions who had been growing cannabis as a drug for quite a few generations . Selecting just for favorable qualities for consumption long before cannabis became a major import to the US .

The only way to enhance UVB is to buy a light specifically designed to produce UVB and use it as a supplement to your grow lights . CMH just happens to have the best spectrum for growth , The UVB spectrum has very little to do with growth .

 

[knna]

I can't view the zipped XML files in the link . Is there anything in those files that isn't shown or explained in the corresponding threads ?

You need to register to see and download attachments. I would upload the spreadsheet here, but AFAIK IC Mag dont allow to upload files other than pics.

The zipped XML files are esential. They are what allows you to calculate bulbs data on radiometric units, aswell as other useful parameters. Threads are only intended to explain how to use the spreadsheet and what mean each calculated parameter.

So i choosed to upload them to rapidshare so you can download them:

OpenOffice spreadsheet (.sxc)

Excell spreadsheet (.xls)

Hand_digitalizer (.sxc)

Hand_digitalizer (.xls)

The hand digitalizer tool is intended to help digitalizing SPD graphs, and it already have some SPDs in it, the phillips CMH between them.

So you believe the proposed UVB benefit of producing THC even with an open hood is not that great with CMH?

In not sold to the idea of UVB promoting higher levels of THC. I dont deny it either, there are evidences wich may suggest both. I believe it should be more effective for breeding high THC strains than to actually increase THC percentage of a given plant. But thats just my very personal opinion.

But i do believe CMHs promote healthier and more resinous plants than HPSs. Its just i dont think its related strickly to UVB, but to the whole spectrum they emit. Ive noticed a huge increase on resin production by adding white leds to an array of blue/red leds, and neither of them emitted any UVB. Maybe UVB plays a role too, but i dont think huge amounts of UVB are required. Its more related to the enhacement of some enzimes, and those biological effects very often requires small amounts of light in order to be triggered. I think full spectrum lamps have better results, and not only about UVB, but the full spectrum from 300 to 800nm. Anyway, these arnt proven facts, just how i see it.

I'm confused. So CMH is hotter than HPS. I was under the impression MH was hottest followed by HPS, with CMH being cool enough that a cooled hood was often not needed. 2) So based on the way I'm reading this if I didn't need an air cooled hood for CMH I wouldn't for HPS either. Is that right?

Total heat released is pretty similar, so you are correct. But CMHs release way more heat by convection (bulb hotter) and way less by IR, so the heat they release is easier to manage and affect plants less. Reduction on heat released to the room by using aircooled hoods is higher when using CMHs than when using HPSs. So although total heat released is similar, ive seen people having more problems controlling temps when using HPS.

ya i was quoted a Spectrograph from Intl Light about a year ago and i cant justify the cost vs the return. (i dont remember exactly but the two charts from the philips PDF to the cmh tested to be wanting to find the exact difference IE if there was a major dif then i would have jumped on philips if that makes sense..

Im on the same situation. Still doing the IE myself, more than 3000$ is too much just for personal research. Ill only buy it if i decide to release a comercial grow light.

however when you think about how far your plants are from the lamp vs philips or other companies saying no uv i truly think they are thinking min distance at like 10 feet for 250 and 15-20 feet for 400 watter.. I could be wrong..

You are right, although small, still there is some UVB emission. I need to install an aditional 100% UV blocking glass when placing a CMH closer than 3ft from products in a shop. I believe its more related to UVA, but ive seen discolored clothes in that situation.

5) How often do CMH's, or any bulb blow up? I would guess not to often as I had not heard of it so far in the thread.

Less than 1 each 100000 bulbs when running properly. Incorrect ballasts, drops of water (beware) may produce it way more often.

6) It's only really dangerous if it happens while you're there in front of it, right?

Saying that sometimes MHs bulbs "explode" may be misleading. As they explode, but not as a bomb, as broken glass pieces often remains in a small circle around the bulb. The bulbs just cracks and make little glass pieces. Its not dangerous at all. What may be dangerous is to inhale vapors coming out the bulb, but you need to be close to it when the bulb brokes (those vapours needs to be very hot and quickly change of physical state). If the residues falls on the plants, i wouldnt smoke them for sure.

But this issue has became very rare on the last years.

8) What are the kinds of things that cause them to blow?

Water reaching a hot bulb is the most often cause, and this is valid too for HPSs. The problem of MHs was small manufacturing defects so small to not be detectable at quality control, but that was aggravated by thermal cycling and vibrations. Ceramic arc tubes have this problem much less (if any).

 

[VirginHarvester]

VirginHarvester , keep in mind that there is no conclusive evidence that UVB is responsible for the enhanced effects of cannabis from tropical regions . Genetics , heat , humidity , soil composition , environmental stress , human selection or a combination of all the above plays just as much as a factor

That brings up another question then, MJ usually grows most potent(I thought) in regions where humidity and temps can be very strong. What I see in grow reports are people trying hard to control heat and humidity, presumably keeping it low. But isn't heat and humidity high in normal MJ grow regions, or are people trying in grow set ups actually trying to keep temp reasonably high and humidity similar to a tropical climate? I think I've seen posts where people keep a humidifier or dehumidifier in their space and temps pretty low, which seems not to be a THC/resin producing environment like Colombia Jamaica or Mexico would be. Just wondering because it seems like people bust it to keep temps below 80 and humidity low, lower than in tropical areas MJ thrives in.

Low humidity = less chance of blowing a bulb?

knna, thanks for all your answers.

Maybe I should skip the idea of complicating my situation of alternating or combining CMH/HPS if CMH tends to produce just as high quality, tight buds. It would be far simpler to just use a 250 or 400w CMH the entire grow unless there's some kind of evidence HPS increases quality in conjunction with CMH, or CMH alone grows an inferior product- which doesn't seem to be the case.

 

[simba]

VH, ill address the Q's to me and add a bit to Knna's response (Great by the way.)

before cmh i had aprox 6-9 harvest's cant really recall. and with cmh about 15 harvest..(green harvests)
Been growing actual veggies for about 10 years indoors.
the stretch nug compactness size etc.. hmm hard to answer.. some strains are Crap IMPHO.. (bread under HPS not mh/hps or cmh or best the outdoor sun)
i would recomend a dropping some $$ on good genetics.. (someone can chime in with good breeder for Full sun plants <outdoor strains now indoors under cmh)
i have dropped my veg time dramatically going to cmh.. that im sure affects side branch's IE shorter veg promotes single to 3 colas.. (short version)

30x30"x60" by that tall. no probs.. keeping cool even without aircooled hood.. and a 250cmh.. might be under powering just a bit. but if heat is any concern 250 in that will be Perfect.IE easy easy to cool...

how often do they blow.. not often.. but when they do. the ceramic arc tube retains that heat longer than a mh arc tube..
if in front it would be minor shrapnel/ shrapnel burns.. they are at 1000c when warmed up.. that wont cool to 100f in 4 feet..
the gases is the other concern..
its rair but its just nevr worth the risk..
Syvania Rep told me that they lost a entire Mfr facility due to a non protected bulb going poof.. in a non enclosed/protected fixture..
the other major reason i say blow on cmh is because the ceramic arc tube has allot more mass vs mh's thin quartz arc tube. thus allowing it to fly further and do more damage.. (not physical persay as the Heat damage IMPHO)


All philips HPS retro whites are Open Fixture rated.. and the ed17 bulbs are avail in open fixture rating.. they will not let any shrapnel past the outer glass.

just use rubbing alcohol 91% on a rag to clean it While power is UNPLUGGED.. (once every 4-6 weeks of use)(If in open fixture..) it will evap and by next morning it will be dry..
just dont manhandle the bulb.. and its ok..

a ballast Wont Turn itself off if there is a problem unless fused and actually blows fuse..

my thing on uv.. is if your cloaning the plant and continuing it on that way over time you might want UVB to keep it from lessinging its natural need for UVB protection> (if the research at hand ends up being confirmed)

the arc tubes is what i was referring.. but knna got it down pat..
if you take a fan and put it directly on a cmh for 20 minutes you will be able to touch it and not burn.. (near end closer to arc tube than tip.. Ya.. not with MH or hps) i posted a pic of doing it many moons ago..

as far as humidity affecting bulb blowing.. nopes...
condensation might be issue if the humidity is up and you drop temps to fast. IE dew point..

i personally think heat and humidity are 100% needed for maximizing production.. (warm and humid allows stoma to work so efficiently and other things.. to)
plants do take up moisture and nutes from air.. look at the rainforest little light but loads of growth and humid hot.. and HIGH C02 on ground level. it gets trapped and plants go wild.. (amazon and deep rainforest)

people are trying to hide more than optimizing plant enviroment.. impho..
add co2 allows higher temps and good growth flower etc.. and as long as humidity isnt to high or low or change to fast its all good..
if you ever get to dewpoint you have problems.. that is Real bad.for flowers.. Mold etc then. and chit growth..
http://apollo.lsc.vsc.edu/classes/idm3020/tut_folder/nick_tutorial/

 

[simba]

side note. on coil around the arc tube.. i kept forgetting to link this.. but its printed and i figured now or never...


here is the Main Patent on the Philips MasterColor CMH lamps..
http://www.freepatentsonline.com/6833677.html
another goody
http://www.freepatentsonline.com/5973453.html

this experp is in no way to imply its uv ouput.. just some info on arc tube..

As used herein, “ceramic” means a refractory material such as a monocrystalline metal oxide (e.g. sapphire), polycrystalline metal oxide (e.g. polycrystalline densely sintered aluminum oxide and yttrium oxide), and polycrystalline non-oxide material (e.g. aluminum nitride). Such materials allow for wall temperatures of 1500-1600K and resist chemical attacks by halides and Na. For purposes of the present invention, polycrystalline aluminum oxide (PCA) has been found to be most suitable.

FIG. 8 also shows a ceramic metal halide arc tube 20 having a conductive antenna coil 50 extending along the length of barrel 22 . As described further hereinbelow, the antenna coil 50 reduces the breakdown voltage at which the fill gas ionizes by a capacitive coupling between the coil and the adjacent lead-in in the plug. When an AC voltage is applied across the electrodes, the antenna stimulates UV emission in the PCA, which in turn causes primary electrons to be emitted by the electrode. The presence of these primary electrons hastens ignition of a discharge in the fill gas.

Thus to summarize, there is provided high wattage discharge lamps which comprise a ceramic discharge vessel which encloses a discharge space and is provided with preferably a cylindrical-shaped ceramic, preferably a sintered translucent polycrystalline alumina arc tube with electrodes, preferably tungsten-molybdenum-cermet-niobium electrodes, attached on either side by gas-tight seals. Metallic mercury, a noble gas or a mixture of noble gases and radioactive 85 Kr, and a salt mixture composed of sodium iodide, calcium iodide, thallium iodide and several rare earth iodides are contained in the arc tube. The arc tube is protected from explosion by a tungsten or molybdenum coil, which also serves as antenna for starting. The entire arc tube and its supporting structure are enclosed in a standard-size lead-free hard glass bulb, with other components such as a getter ( 18 in FIG. 8 ) or an UV enhancer (not shown) attached as necessary.

Molybdenum Coil

As discussed above, for reducing the risk of non-passive failure, a molybdenum coil wrapped around the arc tube and around the extended plugs is used as disclosed in U.S. patent application Ser. No. 09/851,443 filed of even date herewith as a divisional application of this application by Sarah Carleton and Kent Collins for “Coil Antenna/Protection For Ceramic Metal Halide Lamps”

This application discloses a Mo coil antenna wrapped around a PCA arc tube and around at least a portion of the extended plugs. The coil antenna serves as an antenna for starting or ignition, provides good capacitive coupling for ignition, has no adverse effect on the efficacy or lifetime properties of the lamps, and also provides mechanical containment of particles in the event of arc tube rupture.

 

[darippa]

Simba,
Just want to make sure I order the right equip. Would I need anything other than the ballast kit, bulb(from the link in your sig), cord, socket, and a ballast housing? The cmh bulb seems like a great product and I will do an actual side by side comparison with 2 identical flowering cabs(specs & conditions) once I get this mother cab fully situated. Thank you.

 

[simba]

if you buy a reflector it should have a socket.. if not youll need one..
other than that you have it all listed..

 

[darippa]

Simba,
Thanks for the quick reply. Appreciate it.

 

[trichburner]

That brings up another question then, MJ usually grows most potent(I thought) in regions where humidity and temps can be very strong. What I see in grow reports are people trying hard to control heat and humidity, presumably keeping it low. But isn't heat and humidity high in normal MJ grow regions, or are people trying in grow set ups actually trying to keep temp reasonably high and humidity similar to a tropical climate? I think I've seen posts where people keep a humidifier or dehumidifier in their space and temps pretty low, which seems not to be a THC/resin producing environment like Colombia Jamaica or Mexico would be. Just wondering because it seems like people bust it to keep temps below 80 and humidity low, lower than in tropical areas MJ thrives in.

Main reason why indoor growers keep temps and humidity down is to decrease chances of mold and rot . The best pot in the world is often said to come from high altitude regions where the climate is more arid and a higher exposure to sunlight . That's not to say that potent grass doesn't come from lowland regions with higher humidity . Chapter 4 of R.C. Clarke's Marijuana Botany is a good read on this subject and also these threads contain some real good info on the subject as well if you haven't already seen them :

http://www.icmag.com/ic/showthread.php?t=36181

http://www.icmag.com/ic/showthread.php?t=42695&page=1&pp=15

 

[FreezerBoy]

Main reason why indoor growers keep temps and humidity down is to decrease chances of mold and rot[/url]

Just to take it a step further, something happens in an enclosed environment
can quickly destroy an entire cab/room grow.

Remember, its a weed. What it will endure and what it will thrive on are two different things.

 

[javtfs]

here is my set up :

1x 400 cmh + 1 x 150 hps + 2 x 26 w uvb repti glo 10.0 on a AAW medium size.

I can´t compare it with anything else because it is my first grow

 

[VirginHarvester]

Main reason why indoor growers keep temps and humidity down is to decrease chances of mold and rot . The best pot in the world is often said to come from high altitude regions where the climate is more arid and a higher exposure to sunlight .

Good point. So higher altitude is less humidity and cooler temps. So often indoor growers keep a dehumidifier close by and running to take humidity out of the room if it's a problem?

here is my set up :

1x 400 cmh + 1 x 150 hps + 2 x 26 w uvb repti glo 10.0 on a AAW medium size.

Awesome javtfs, I would like to emulate something like your setup. I take it you have a dual lamp, which model? And how do you connect or integrate the uvb bulb into your grow lamp? Does it create a lot of heat and and do you have it on a separate timer so it doesn't stay on all the time?

Thanks.

 

[javtfs]

No , I don´t have a dual lamp , it is just a 400 cmh and a 150 hps fitted in the same reflector , The uvb bulbs are " attached " to the cmh and hps socket wires . The cmh and hps run for 12 hours and the uvb run on a separate timer 3 hours a day.

I don´t know if it is correct but that is what I am doing.

Talking about temperatures ... well it is summer over here and with the lights on it reaches 87 F , with the lights off about 82 F.

The only thing that piss me off is that I think I have crappy strains ( dutch passion skunk and euforia , this last one I think is a waste of time )

Thanks for your comments