Ceramic Metal Halide (CMH) - Page 2 - Growroom Lighting - International Cannagraphic Magazine Forums

simba · 10-28-2007, 10:51 AM

after testing many ELEC ballasts in CMH catagory VS came up on top.. Adv tech sells them 20-150 watt, and looking at advance's versions.. as advance has 20-400 watt E-ballasts..

ya Venture lighting has a Full SPD HPS RETRO Lamp also.. it dont compete with philips CMH,
<<<<~~has allready looked and no go..
philips, eye, osram, GE, venture (few others) have a CMH but not what philips has..

as far as a case any metal box or even a DIY Sheetmetal Box.. Just make sure u give it airflow (lowers its overal temp)

yes MPL ur link on post 10 will work just fine..

Pirate138 · 10-28-2007, 12:21 PM

nice thread, ive been wanting to buy a CMH and will soon. i heard they give off alot less heat and you can get the light closer to your plants without burning them. when ordering a bulb, we usually use horizontal bulbs right in a normal hood?

gladysvjubb · 10-28-2007, 12:34 PM

Has anyone actually flowered using CMH? I would just use it for 12/12 only. I've got my eye on one to purchase, just want to make sure it's ok to flower with.

Pirate138 · 10-28-2007, 12:40 PM

yeah ive seen some grow threads where people are flowering with CMH

10-28-2007, 02:21 PM

Has anyone flowered? Let's see here.......

chimei · 10-28-2007, 08:24 PM

I just want to confirm a few things.

The Horizontal CMH 400 watt Philips bulb can be used in a non enclosed hood right? I have been using it that way for awhile and thought it was OK.

I thought I read that the odds of one of these CMH bulbs exploding compared to MH and HPS standard bulbs is decreased. (Something about the wire wrapped around the element in the middle?)

Which is worse when exploding? MH or HPS?

I keep reading that you should be able to get it closer to the plants. This is even when it is not enclosed? (Assuming you have good ventilation in the room and temps are decent)

This is my first run with CMH, still in Veg.

When I used to do MH then HPS for flower I always noticed I could get allot closer to the bulb with MH, HPS always tended to bleach or burn when I got as close as I did with MH.

I think one time I used strictly a MH for veg and flower I would be as close as 4-5" at times with the colas.

With HPS I always have to keep at least 12"+ or I would get bleaching and under developed bud sites because they were stressed. Those of you that have done complete cycles with CMH, in flowering in a non enclosed hood how close were you getting to your tops with your CMH bulb out of curiosity?

I have had a 400 watt Switchable ballast for years now. My 400 CMH Philips works great when I put the ballast on HPS and run the lamp, as long as you have a 400 Watt HPS ballast (or switchable one set to HPS) you can run one of these bulbs right? There are no other specifics the ballast needs to support? It's been running fine for awhile now, just want to make there is nothing I missed and I have a fire hazard.

Thanks!!

10-28-2007, 08:49 PM

I don't worry about arc tube explosion or failure as I believe it to be rare when the bulbs are running as prescribed by the manufacturer. Yes it is open fixture rated. Yes you can get closer but, every set-up differs some so watch and move the lights down in steps. I allways start a little high and then work down as every strain has different tolerances. I also move it and wait one day. I have some aggressive Jhonny Blaze and one of them has been into my PL midi reflector before burning.

This is a great bulb fore cloning folks. Perfect energy ballance for rooting.

MPL · 10-28-2007, 10:35 PM

I was thinking about the PL Deep or Midi reflector. The deep seems like it would be best for my application, since I'm growing in a square. Are these reflectors pretty good? I have read nothing but positive reviews, but not many people seem to be using them. Also, the deep says it recommends a height above the plants of 24" to cover a 3'x3' area. Would it hurt to lower the light to gain intensity? I was hoping to keep it 12" or lower above the highest colas...

simba · 10-29-2007, 09:54 AM

ya the failures are rare but do happen..

PL reflectors are Designed odd..
they height they say for 3x3 is what u need.. its a very controlled output...
you will have to play with it....
(while ur plants are babies Young flowering.. you can move them closer together if ur going to have a pl deep at 2.5 or less feet up..

but a PL deep at its prescribed Height will give you a better pattern/output than another reflector at a lower height in comparing the two... (if that makes sense) but ya it would be nice to be able to lower the hood and adjust the output.. (coming!! Ya!)
Think of PL reflectors as PAR FLood lamps (security flood lamp) with no wasted light on the walls
as you raise the flood off the ground the circle spot gets bigger.Same with PL DEEP>.
ya PL is not the most common for Hobie growers. as they prety much designed for use at higher Rated Heights for greenhouses so all they gota do is relamp and get good light spread/output..

ya
horizontal --

Vertical |

think if ur plants ever go horizontal u got MAJOR Problems LoL.. or Horizontal for Horizon

think of these like HPS popping, (just arc tube failing,or rupture but contained)
MH operates at higher arc tube pure so when it pops it Blows... (IE The BIG ROUND BULBS are rated Open fixture as they designed to hold that blast)
but cmh runs at the pressure of MH but with HPS arc tube (basicly) and that hps arc tube is stronger than typical MH glass arc tube.. and with the extra protection of the paper clip looking tie.. it all holds together may just crack into pieces but wont PLAT the outer wall..

MPL · 10-29-2007, 10:23 AM

So let me make sure I understand...

If I use a PL deep hood all I have to do to adjust its footprint is to raise or lower it... which is what I've been assuming all along. It looks like what I'm going to end up with so long as I don't get any negative feedback for it.

With a 400w CMH in a smallish cabinet, is aircooling required as it would be for a HPS? I plan on pulling around 200-300 cfm through the cabinet. My ambient temperature are around 70F.

10-28-2007, 10:51 AM	#11
simba Sleeping Dragon Join Date: Dec 2005 Location: Somewhere Out There Posts: 983	after testing many ELEC ballasts in CMH catagory VS came up on top.. Adv tech sells them 20-150 watt, and looking at advance's versions.. as advance has 20-400 watt E-ballasts.. ya Venture lighting has a Full SPD HPS RETRO Lamp also.. it dont compete with philips CMH, <<<<~~has allready looked and no go.. philips, eye, osram, GE, venture (few others) have a CMH but not what philips has.. as far as a case any metal box or even a DIY Sheetmetal Box.. Just make sure u give it airflow (lowers its overal temp) yes MPL ur link on post 10 will work just fine.. __________________ CMH ~ Ceramic Metal Halide Growers ~ World Wide Social Group "Be who you are and say what you feel, because those who mind don't matter, and those who matter don't mind." Theodor Seuss Geisel We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology." Dr. Carl Sagan My Dr. has Recommended Medical Marijuana for the Treatment of my Ulcerative Colitis I’m also prescribed Marinol (4, 5mg capsules Per day) Cost is Aprox $1,200.00 Per Month[/color]
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10-28-2007, 12:21 PM	#12
Pirate138 the Revenant Join Date: Aug 2007 Location: Dirty South Posts: 1,460	nice thread, ive been wanting to buy a CMH and will soon. i heard they give off alot less heat and you can get the light closer to your plants without burning them. when ordering a bulb, we usually use horizontal bulbs right in a normal hood?
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10-28-2007, 12:34 PM	#13
gladysvjubb Member Join Date: Apr 2007 Posts: 469	Has anyone actually flowered using CMH? I would just use it for 12/12 only. I've got my eye on one to purchase, just want to make sure it's ok to flower with. __________________ And remember kids, always use Grandma's Molasses at 1 teaspoon per gallon for your last few waterings, you'll be glad you did......check on ebay for Grandma's, I found a couple there. https://www.icmag.com/ic/showthread.p...light=molasses Home distilled water: Check on ebay for countertop distillers. Insects got you down? Try HOTSHOT No Pest Strips (NPS). Say goodbye to spider mites, etc. $20 Hash Press https://www.icmag.com/ic/showthread.php?t=47524 Fully contained self watering planters: https://www.naturalspring.com/natsprinplan.html How to transplant stress free: https://www.icmag.com/ic/showthread.p...94#post1500194 Need durable Plant Markers? Cut an old venetian blind to your size and label with a Sharpie! Overgrow the world ***ANYBODY for President *** The only WOODSTOCK I saw was the WOODSTOCK of my M-14 rifle.
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10-28-2007, 12:40 PM	#14
Pirate138 the Revenant Join Date: Aug 2007 Location: Dirty South Posts: 1,460	yeah ive seen some grow threads where people are flowering with CMH
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10-28-2007, 02:21 PM	#15
Guest Guest Posts: n/a	Has anyone flowered? Let's see here.......
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10-28-2007, 08:24 PM	#16
chimei Member Join Date: Sep 2007 Posts: 204	I just want to confirm a few things. The Horizontal CMH 400 watt Philips bulb can be used in a non enclosed hood right? I have been using it that way for awhile and thought it was OK. I thought I read that the odds of one of these CMH bulbs exploding compared to MH and HPS standard bulbs is decreased. (Something about the wire wrapped around the element in the middle?) Which is worse when exploding? MH or HPS? I keep reading that you should be able to get it closer to the plants. This is even when it is not enclosed? (Assuming you have good ventilation in the room and temps are decent) This is my first run with CMH, still in Veg. When I used to do MH then HPS for flower I always noticed I could get allot closer to the bulb with MH, HPS always tended to bleach or burn when I got as close as I did with MH. I think one time I used strictly a MH for veg and flower I would be as close as 4-5" at times with the colas. With HPS I always have to keep at least 12"+ or I would get bleaching and under developed bud sites because they were stressed. Those of you that have done complete cycles with CMH, in flowering in a non enclosed hood how close were you getting to your tops with your CMH bulb out of curiosity? I have had a 400 watt Switchable ballast for years now. My 400 CMH Philips works great when I put the ballast on HPS and run the lamp, as long as you have a 400 Watt HPS ballast (or switchable one set to HPS) you can run one of these bulbs right? There are no other specifics the ballast needs to support? It's been running fine for awhile now, just want to make there is nothing I missed and I have a fire hazard. Thanks!! Last edited by chimei; 10-28-2007 at 08:29 PM..
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10-28-2007, 08:49 PM	#17
Guest Guest Posts: n/a	I don't worry about arc tube explosion or failure as I believe it to be rare when the bulbs are running as prescribed by the manufacturer. Yes it is open fixture rated. Yes you can get closer but, every set-up differs some so watch and move the lights down in steps. I allways start a little high and then work down as every strain has different tolerances. I also move it and wait one day. I have some aggressive Jhonny Blaze and one of them has been into my PL midi reflector before burning. This is a great bulb fore cloning folks. Perfect energy ballance for rooting.
	Quote

10-28-2007, 10:35 PM	#18
MPL Member Join Date: Oct 2007 Posts: 791	I was thinking about the PL Deep or Midi reflector. The deep seems like it would be best for my application, since I'm growing in a square. Are these reflectors pretty good? I have read nothing but positive reviews, but not many people seem to be using them. Also, the deep says it recommends a height above the plants of 24" to cover a 3'x3' area. Would it hurt to lower the light to gain intensity? I was hoping to keep it 12" or lower above the highest colas... Last edited by MPL; 10-29-2007 at 10:24 AM..
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10-29-2007, 09:54 AM	#19
simba Sleeping Dragon Join Date: Dec 2005 Location: Somewhere Out There Posts: 983	ya the failures are rare but do happen.. PL reflectors are Designed odd.. they height they say for 3x3 is what u need.. its a very controlled output... you will have to play with it.... (while ur plants are babies Young flowering.. you can move them closer together if ur going to have a pl deep at 2.5 or less feet up.. but a PL deep at its prescribed Height will give you a better pattern/output than another reflector at a lower height in comparing the two... (if that makes sense) but ya it would be nice to be able to lower the hood and adjust the output.. (coming!! Ya!) Think of PL reflectors as PAR FLood lamps (security flood lamp) with no wasted light on the walls as you raise the flood off the ground the circle spot gets bigger.Same with PL DEEP>. ya PL is not the most common for Hobie growers. as they prety much designed for use at higher Rated Heights for greenhouses so all they gota do is relamp and get good light spread/output.. ya horizontal -- Vertical \| think if ur plants ever go horizontal u got MAJOR Problems LoL.. or Horizontal for Horizon think of these like HPS popping, (just arc tube failing,or rupture but contained) MH operates at higher arc tube pure so when it pops it Blows... (IE The BIG ROUND BULBS are rated Open fixture as they designed to hold that blast) but cmh runs at the pressure of MH but with HPS arc tube (basicly) and that hps arc tube is stronger than typical MH glass arc tube.. and with the extra protection of the paper clip looking tie.. it all holds together may just crack into pieces but wont PLAT the outer wall.. __________________ CMH ~ Ceramic Metal Halide Growers ~ World Wide Social Group "Be who you are and say what you feel, because those who mind don't matter, and those who matter don't mind." Theodor Seuss Geisel We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology." Dr. Carl Sagan My Dr. has Recommended Medical Marijuana for the Treatment of my Ulcerative Colitis I’m also prescribed Marinol (4, 5mg capsules Per day) Cost is Aprox $1,200.00 Per Month[/color] Last edited by simba; 10-29-2007 at 10:20 AM..
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10-29-2007, 10:23 AM	#20
MPL Member Join Date: Oct 2007 Posts: 791	So let me make sure I understand... If I use a PL deep hood all I have to do to adjust its footprint is to raise or lower it... which is what I've been assuming all along. It looks like what I'm going to end up with so long as I don't get any negative feedback for it. With a 400w CMH in a smallish cabinet, is aircooling required as it would be for a HPS? I plan on pulling around 200-300 cfm through the cabinet. My ambient temperature are around 70F.
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