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Ceramic Metal Halide (CMH)

zachrockbadenof

Well-known member
Veteran
About 2yrs ago i wanted to build this, and it finally has become a reality. my 2nd flower room at a new location.

Freshly built unistrut / c-channel 11ft x 12ft light mover with 6 kingbrite cs650 watt 3 channel leds. 3 independent led channels , fullspec, uv, far red. meanwell ballasts,lm301h, then i think lg uv or red diodes, i forget atm.

then 9 315w phillips master color 4200k vert bulbs. Cmh wired for 2 independent or combined light / lantern patterns. one circuit wired like a " number 5 on a dice". the other is a 4 pointed diamond, or a square turned 90 degrees.

Last spot i ran these cmh setup in between de 1000's and never ran wattage above 750w. great results. so i wanted to try them with leds

pic at start up
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nice....
 

k-s-p

Well-known member
Veteran
I doubt there is a big difference. Slightly more compact plants. Interesting experiment anyway. Will you be using the same plants and grow style?

Hey man sorry I missed this.

Yes, I'll be using the same plants (clones) and setup. Found a Philips 4200K today online for under $19 taxes included - "used: like new". So I'll start the next cycle with it.
 

Kimes

Well-known member
About 2yrs ago i wanted to build this, and it finally has become a reality. my 2nd flower room at a new location.

Freshly built unistrut / c-channel 11ft x 12ft light mover with 6 kingbrite cs650 watt 3 channel leds. 3 independent led channels , fullspec, uv, far red. meanwell ballasts,lm301h, then i think lg uv or red diodes, i forget atm.

then 9 315w phillips master color 4200k vert bulbs. Cmh wired for 2 independent or combined light / lantern patterns. one circuit wired like a " number 5 on a dice". the other is a 4 pointed diamond, or a square turned 90 degrees.

Last spot i ran these cmh setup in between de 1000's and never ran wattage above 750w. great results. so i wanted to try them with leds

2 points: with being able to control cmh at 45% (4lights) or 55% (5lights) or 100% (all 9 lights), then dimm the leds to match wanted light ppfd/dli. Hoping to get the point where the cmh will add extra heat to the room to prevent dehumidifier from cycling during lights on. Allowing the high efficiency AC to run a little harder therefore pulling more hummidty from the room. (less energy then running quest dehumidifier)

Or 2, adding heat to the room during the winter.

Well, all in a theory, maybe, only one way to find out


pic at cmh start up
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Woul love to hear more about this setup all in all, plz

greetz,

Kimes
 

gmanwho

Well-known member
Veteran
Hey Kimes, i go into a little detail over here. post #3


Still working the kinks. But i can say the cmh portion is doing as intended, creating heat and usable light at the same time. As soon as i fired the cmh up at like day 20 of flower, the room went immediately to adding hummidity instead of running the dehumidifier.

the dehumidifier uses about 8-900 watts. the cmh setup running all 9 lights uses uses 2835 watts.

quick math, im running 3 cmh lights instead of a dehumidifier!
then an additional 2000w of light.
and maybe 30 watts for the centrifugal motor on the humidifier.
unknown amount of energy for the 36kbtu mitsubishi 20 seer mini split to remove that 2030 watts of added heat.
 

CDMHog

Member
Pretty sure I still have a stash of the Philips Retro-white 400w ceramic metal halide lamps, that you used in a 400 watt HPS fixture. Also have a box of the CDM 860W ceramic metal halide's that work with a regular 1000w metal halide ballast. Old skool bulbs.
 

CDMHog

Member
2023 and still rockin with vintage CMH! Here's a couple pics of some lamps I still have. I bought these a long time ago on Ebay. Was always and still am into Philips stuff, so I only used Philips lamps. Here's some pics and spectrum's of them.

Stash of 5 - CMH 400w Retro-white conversion lamps. These run in a 400w HPS magnetic ballast. I have 3 vertical and 2 horizontal. My fixture can work both ways. These have a great spectrum imo. I did one grow with them and the plant turned out nice. The green ended ones are horizontal.
20230912_075902.jpg


Retro-white spectrum. The spectrum is shown from 400-700nm. There are peaks at 450nm, 550nm, 600nm and 680nm. It results in a very balanced light with a red tinge to it.
Retrowhite spectrum jpg.jpg



Here's my stash of Philips CDM Allstar 860w lamps. These run in a regular magnetic, 1000w metal halide ballast. They also have a great spectrum and run 140w less.
20230912_075033.jpg


860w spectrum. This graph shows that the lamp has a good balance, with some far-red peaks.
CDM ALLSTAR 860W.jpg


There are still companies that sell CMH conversion lamps for HPS. IMO, for HID they are hard to beat. I was never a fan of HPS because I'm a huge proponent of blue and UV light. I like metal halides's.
 
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przcvctm

Well-known member
Veteran
I know. I know. Search function. Since individual threads can no longer be searched (or if they can, I don't know how on this new format) I'm just going to ask. Money no object, what is the best remote ballast and vertical 315w reflector?

I've been a happy Philips lamp user for 15 years but my last Retro-White has a lot of hours on it and it's time for new technology.

TIA
 

Koondense

Well-known member
Veteran
Good question, I would also like to know the answer.
Looking at the Growlite reflector, looks interesting and they sell it separately or with ballast+bulb.
However here in Europe I would go with the Lumatek ballast and Secret Jardin parabolic reflector for cmh.

Cheers
 

goingrey

Well-known member
I know. I know. Search function. Since individual threads can no longer be searched (or if they can, I don't know how on this new format) I'm just going to ask. Money no object, what is the best remote ballast and vertical 315w reflector?

I've been a happy Philips lamp user for 15 years but my last Retro-White has a lot of hours on it and it's time for new technology.

TIA
The Secret Jardin reflector @Koondense mentioned proved excellent in some test, might have been on the Migro Youtube channel. Probably the best one from a light distribution POV. But it's mylar coated fabric. Sheet metal feels safer from a fire hazard perspective. Then again the tents are also the same material so..

For ballasts some people say that the cheap magnetic ballasts are actually better than the fancy digital ones? Better as in more efficient. Digital might have longer bulb life and dimming and so on.

And for searching in a thread click "Search" and then choose "This thread".

1695658539093.png
 

radioman

Active member
I still like the "old lights" myself. Yes, I switched to LED"s like everyone else. I'm not a big grower - just a small time, grow a few plants for myself person. I only have a few LED grows under my belt vs. years of "old lights". - However, I think I grew better Cannabis with the "old lights" - using my own seeds that I bred myself vs. LED lights and "store bought" clones + "store bought" female seeds...
I could be just Me though. Maybe I'm still learning to use the new products available since legalization here in Vermont...
My next grow - this winter - I'm going to use my own seeds, my own soil and the old Hydrofarm Light (for awhile anyway). Then switch over to the LED's later on. I'll keep the expensive Female Seeds (from the shop) in the fridge for now...
Everything is still evolving here with legalization. The shops are mostly charging too much money for their products. I wanted to switch over and be completely legal after this year - but i can't afford it...
 

jwm

Well-known member
Veteran
2023 and still rockin with vintage CMH! Here's a couple pics of some lamps I still have. I bought these a long time ago on Ebay. Was always and still am into Philips stuff, so I only used Philips lamps. Here's some pics and spectrum's of them.

Stash of 5 - CMH 400w Retro-white conversion lamps. These run in a 400w HPS magnetic ballast. I have 3 vertical and 2 horizontal. My fixture can work both ways. These have a great spectrum imo. I did one grow with them and the plant turned out nice. The green ended ones are horizontal.
View attachment 18889200

Retro-white spectrum. The spectrum is shown from 400-700nm. There are peaks at 450nm, 550nm, 600nm and 680nm. It results in a very balanced light with a red tinge to it.
View attachment 18889208


Here's my stash of Philips CDM Allstar 860w lamps. These run in a regular magnetic, 1000w metal halide ballast. They also have a great spectrum and run 140w less.
View attachment 18889205

860w spectrum. This graph shows that the lamp has a good balance, with some far-red peaks.
View attachment 18889206

There are still companies that sell CMH conversion lamps for HPS. IMO, for HID they are hard to beat. I was never a fan of HPS because I'm a huge proponent of blue and UV light. I like metal halides's.
Love CMH! Used them for years, years ago. Since then I’ve switched to LED w/ similar results.
 

Azeotrope

Well-known member
Veteran
I am still using LEC/CDM/CMH bulbs. I use the 150w and 70w G12 bulbs. 2 qty of the 150's horizontal in a reflector, 1 qty 150w vertical, and 1 qty 70w vertical. All on digital/electronic ballasts. This allows me to select a combo of 930 and 940/942 bulbs as I desire. I have attached some pics of a previous grow of GoldenTigerxSnowMoon near harvest in a 30" x 30" tent. About 41w/sqft on that one. Also of my current random selection of Zamdelica/GoldenTiger/Guwai @ day 5 12/12 in a 39"x39" tent with a total of 520w or about 49w/sqft.

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BakedApe

New member
Vertical barebulb CMH

From what I remember, binge reading the 315W thread years ago, not all CMH can hang vertical? And it was also some difference between bulbs for open and closed fixtures, and some advantages with open rated bulbs? Was it UV?

Of course, they have the risk of blowing up in your face, but growing vertical, I'm thinking the lights could just as well be turned off to spare the eyes anyway... how long does a CMH has to be turned off before turning on again?

What specs do I look for to find vertical ones, and open fixture rating? I rarely see anything in plain text in the regular grow shops?
Last time I was reading up on the subject, the pyramid/prism? guy was the go-to, but he was very unreliable?
What are the go-to shops for CMH these days?

Are there bulbs lower than 315W to be found, with the mentioned specs?
Tinkering with the idea to run a small vertical CMH inside a 8-16 manifold..
 

hillbil

Active member
Old Philips 250w and 400w CMH bulbs were made to operate vertically or horizontally, not both. Most used the 4000k. You chose which one when you bought them. They are too hard on my eyes for bare bulb, had welder flash a few times with old CMH rated for open fixtures.
Using up NIB bulbs from 10 years ago for added UVA as well as IR since LEDs have neither.
 
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