Ceramic Metal Halide (CMH) Thread

jr22hockey

Well-Known Member
Ceramic Metal Halide bulbs seem to be an undiscovered technology here on Rollitup.

For those of you who don't know, CMH's are a new kind of HID light that has a much fuller spectrum of light. It has more blue than a metal halide and more red than an HPS. A CMH bulb plugs into a magnetic HPS ballast (not digital). The grows that I've seen that use CMH light have leafier buds, but tighter and more potent buds.

One of the best parts of the CMH is that it is cool enough to touch.

If anyone has ever used a CMH bulb in their grow, please give some input so the RIU community can come to a verdict on them.

Also feel free to post pictures of your CMH grow
 

Green Cross

Well-Known Member
Ceramic Metal Halide bulbs seem to be an undiscovered technology here on Rollitup.

For those of you who don't know, CMH's are a new kind of HID light that has a much fuller spectrum of light. It has more blue than a metal halide and more red than an HPS. A CMH bulb plugs into a magnetic HPS ballast (not digital). The grows that I've seen that use CMH light have leafier buds, but tighter and more potent buds.

One of the best parts of the CMH is that it is cool enough to touch.

If anyone has ever used a CMH bulb in their grow, please give some input so the RIU community can come to a verdict on them.

Also feel free to post pictures of your CMH grow
See the first harvest in my journal for the results. And stay tuned for the next few weeks for a HPS comparison.

I haven't seen a lot of difference; Like you said there is a little more leaf to trim, but more resin production = more potency. The buds are less dense though I think. The plants looked healthier, and there was little stretch.

If I wanted to use only one bulb, and had a magnetic ballast, I'd definitely choose the CMH over HPS.
:leaf:
 

Green Cross

Well-Known Member
awesome, I think Ill try it out. What makes you say it runs cooler? I assume you dont mean light spectrum
CMH bulbs do throw less heat, than HPS, but I still have to keep the plants a few inches away.

You should also wear eye protection, when working close to them, because they also put out a lot of UV.

These CMH bulbs (retro white) come in 250 and 400W only, and come in 2 varieties - Vertical/horizontal burn - depending on your fixture.
 

riddleme

Well-Known Member
Well I'm subscribed so I might as well help out,,,,,,

For those that have not done extensive research I would like to point out that there is one specific CMH bulb that is best and the reason is that some of them have a layer of UV blocking filters

here is a link (not saying to buy it here, but this link gives the phillips part number)
http://www.growlightexpress.com/ceramic-metal-halide-bulbs-9/mastercolor-ceramic-metal-halide-250-watt-horizontal-87.html

to "the" bulb you want if your going CMH (there is also a 400 watter, they have it as well)

There is a thread on icmag that is over 2 years long (still active) and over 200 pages that is a must read if your leaning towards this bulb. (simply google "ceramic metal halide" and it comes up)
There are several test and comparrison grows and even a photo of a guy holding the bulb while it is on (totally answering the less heat question)

It is simply put the best light you can currently get for a personal medical grow, do the research and you'll see what I'm saying :bigjoint:
 

mafia

Well-Known Member
i saw that pic. i also use a phillips 400w cmh and id burn my fingers if i touched it like that after it warms up
its even warm after i let it sit and cool down for 10 minutes to switch bulbs
 
Top