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Ceramic Metal Halide (CMH)

S

scurred

Member
Well you all convinced me to try CMH! I didn't order from advancedtech, found a local place that offered em for around the same place, but it's the same bulb that these guys are promoting.

Switched out the HPS bulb from my HTGSupply 400w HPS ballast and the CMH bulb powered on perfectly. Pretty quick start, flickered through some reds, blues and purples for a few minutes before settling on the white light - but it was quick and seemed to work.

We were using a 400w MH 6500k bulb/ballast and I was noticing weird growth under it. Plants directly under the reflector were growing perfectly. But the other plants not directly under it were stretching like crazy, up to 3.5" of internode spacing. So I am hoping the CMH will give better coverage.

We plan to use the CMH for veg and flower this run, but eventually we will be vegging under T5 flourescents and only flowering under HID.

I will update in a couple weeks when I test with the CMH a bit more. Thanks for all of the information in this thread!
 
S

scurred

Member
Not too sure how much less heat is being generated by CMH, my MH setup 400w put out less heat, but the CMH does disperse heat differently than HPS, the HPS like radiates heat in all directions and feels much hotter on my skin, but the room temp is the sme with HPS and CMH for me. Still too early to say how growth is with CMH though but everythings ok so far!
 
W

whiterasta

CMH makes a huge difference in efficiency from what i have seen in my grow.
I am getting better results so far with.8k CMH than 1k MH so far in the beginning of this cycle I am running 3hrs CMH lead in and out with 12hrs combined CMH/HPS @ 2.8k. veg and 2hrs lead in and out CMH with 8hs combined flowering this cycle and am impressed at how the plant look just a few days out of the clone closet with meristem growth two nodes ahead of the same using MH. Same strain and cloning tek for both.
here are some comparison pics of the same views @ .8kCMH and 2.8k combined CMH/HPS

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See how the CMH whitens the HPS? here is a single plant to compare the light color

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I am running dual foci parabolics which seem to mix the spectra very well and really disperse the light very conically

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WR:tiphat:
 
B

bbspills

New member
CMH last week of flowering

CMH last week of flowering

What are peoples thoughts on switching to CMH the last week of flowering?

Should I just stick with the HPS or use the CMH?
 
K

khysanth

New member
Bit the bullet and picked up a Phillips 400w CMH.

I want to buy the 400w Ballast kit from them, but can't find any solid DIY guides on here (other than a 400w MH DIY, which is different from an HPS ballast).

Has anyone done a DIY 400w ballast for your 400w CMH? I could definitely use a few pointers because I'm looking forward to the experience and saving ~$150. :p
 
O

onegreenday

Active member
Veteran
regular grounding practices.
ground the ballast and the lamp/fixture cord .
I don't mind an 'open' ballast or a milk crate with
a wood cover for a warming tray but
a vented metal box is safer in case of fire.
 
D

dingbang

So I am trying to help a friend set up a small closet grow with a 150w CMH but have some confusion on what type of ballast we need. I already have a 150w pulse start metal halide ballast from an aquarium. Will this work?
 
messn'n'gommin'

messn'n'gommin'

ember
Veteran
250w and 400w lamps operate on magnetic core and coil HPS ballasts.

The 70w, 100w, and 150w lamps operate on magnetic core and coil pulse start MH ballasts.

Be sure to match the ANSI codes.

hth
 
D

dingbang

messn'n'gommin' said:
250w and 400w lamps operate on magnetic core and coil HPS ballasts.

The 70w, 100w, and 150w lamps operate on magnetic core and coil pulse start MH ballasts.

Just match the ANSI codes.

hth
Click to expand...

Thanks messn'n'gommin'.

The ANSI code for the lamps we have are M102/M142/E so we need a M102 ballast? M102 is pulse start MH correct?
 
D

dingbang

So messn'n'gommin' was right. Thank you.

The 150's and under will need a pulse start MH ballast.
Thanks to everyone for a great thread. I can't wait to compare CMH to HPS side by side.
 
S

SSLcloner

New member
hope this doesnt cause any confusion, but philips makes the true pulse start cmh lamps up to 250 watts and all will work with a suitable M102/M142 ballasts whether coil/core or electronic. dwarfganja is refering to the cmh RETRO lamps that are designed for coil/core hps ballasts only. Those come in 250w and 400w.
 
messn'n'gommin'

messn'n'gommin'

ember
Veteran
SSLcloner said:
hope this doesnt cause any confusion, but philips makes the true pulse start cmh lamps up to 250 watts and all will work with a suitable M102/M142 ballasts whether coil/core or electronic. dwarfganja is refering to the cmh RETRO lamps that are designed for coil/core hps ballasts only. Those come in 250w and 400w.
Click to expand...

An excellent point! I sometimes forget that there are other formats for CMH technology and this thread is mostly based on the Phillips RETROWHITE.

Thanks for the clarification!

namaste
 
W

whiterasta

dingbang said:
So messn'n'gommin' was right. Thank you.

The 150's and under will need a pulse start MH ballast.
Thanks to everyone for a great thread. I can't wait to compare CMH to HPS side by side.
Click to expand...

So far the main difference I have seen using a combination
1K HPS/.4k CMH is my plants are much more compact and with closer nodes by about 50%, comparing old photos. Stems are thicker and stiffer and overall leaf texture is coarser.
My leggiest strain is behaving tight and compact with ~twice the nodes per branch as HPS alone. Will turn back soon and we will see if the extra nodes turn into more buds.
So far however things really look the best I have seen under lights and as good as a number of greenhouses.
WR:tiphat:
 
D

dingbang

Thanks for clarifying SSLcloner. If I recall correctly you made your rig, right? If so what bulb/ballast combo are you using?

I already have a case of the 150w MasterColor Alto 4K lamps made by Philips which is why we are matching our ballast to our bulbs rather than a more logical inverse manner. Are the Retro bulbs better suited for horticulture use?

Thanks again to everyone and I am sorry if my questions are redundant.
 
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