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Ceramic Metal Halide (CMH)

messn'n'gommin'

ember
Veteran
I think it less Kelvin temperature as much as it is the lamp architecture. Phillips markets two versions, "Protected" and "Unprotected" and either is sold with both Kelvin ratings. Protected means that if a catastrophic failure occurs (and any HID lamp can), the bulb will contain it. Unprotected is only to be used in a fixture that is designed to contain a lamp failure. Don't use the Unprotected version.

If you want to add more red, I would just opt for a generic HPS bulb. But, that is a problem for wattages of 150 and below. For pulse start MH ballasts it may be that the CMH 3000K is the only real option for more red.
 

gumball

New member
I think it less Kelvin temperature as much as it is the lamp architecture. Phillips markets two versions, "Protected" and "Unprotected" and either is sold with both Kelvin ratings. Protected means that if a catastrophic failure occurs (and any HID lamp can), the bulb will contain it. Unprotected is only to be used in a fixture that is designed to contain a lamp failure. Don't use the Unprotected version.

If you want to add more red, I would just opt for a generic HPS bulb. But, that is a problem for wattages of 150 and below. For pulse start MH ballasts it may be that the CMH 3000K is the only real option for more red.

Thanks for the good info messn. Well I have the unprotected 4k I am pretty sure. Thankfully it is not near anything flammable, just a metal PC case. I thought about getting an HPS, but I would like to be able to use the same ballast, so I think I will stay with the 3k CMH. From my reading the lower kelvin bulbs help the buds swell more so at the end of flower, and give more stretch. I like tight internodes, but I like the stretch oftoo.
 
B

blueberry dank

They don't really run cooler, they just don't throw as much radiant heat onto your plants, the heat tends to stay in the reflector - closer to the bulb.

You never really NEED a air cooled reflector, the only time you would need this is if you wanted to get your light within 6" of your plant tops, or wanted to run a sealed room with co2.

As long as you have an exhaust fan and enough passive or active intake, your closet will stay cool. Just run the exhaust at all times when your light is on.

Even if I run 2 400 HPS in a smallish closet?..whats the limit on this?
 

messn'n'gommin'

ember
Veteran
Thanks for the good info messn. Well I have the unprotected 4k I am pretty sure. Thankfully it is not near anything flammable, just a metal PC case. I thought about getting an HPS, but I would like to be able to use the same ballast, so I think I will stay with the 3k CMH. From my reading the lower kelvin bulbs help the buds swell more so at the end of flower, and give more stretch. I like tight internodes, but I like the stretch oftoo.

NP man!

As an aside, it's none of my business how you run your grow, but, if you're using the unprotected version...you're walking an edge I wouldn't!
 
B

blueberry dank

Can I run two uncooled 400hps in a smallish closet...as lnog as I have enoguh exhaust and negative pressure..and passive intake..I know Ill manage a sinlge bulb like this..but what about TWO?....is negative pressure really that good at removing all heat?...
 

messn'n'gommin'

ember
Veteran
With two 400's in a 2x4 closet equates to 100w's/sqft. A bit on the high end...but doable. I'm using two 250's in batwing reflectors for roughly a 2x4 closet, but, I have somewhere in the vicinity of 60 sq/in's of passive air flow and a 6" 600+ cfm fan plugged into a variac transformer operating at about 60% power. After it is all said and done, I'm guessing I'm at about 250-275 CFM. So yes, you're going to need a good ventilation system as heat buildup from two 400's will demand a bigger setup than mine!
 

Baba Ku

Active member
Veteran
Yeah, Pin..I would make sure it wasn't a capacitor that went out. If the bulb didn't give any indications of fail, it may not have. Have you fired the hps yet?
 

Pinball Wizard

The wand chooses the wizard
Veteran
Yeah, Pin..I would make sure it wasn't a capacitor that went out. If the bulb didn't give any indications of fail, it may not have. Have you fired the hps yet?
The HPS bulb worked fine. The CMH bulb had no 'Getter Flash' and the glass bulb had turned cloudy.
It's fucked.

The Pre-Burned look at the base of a new lamp is more important than I thought!
 

Anti

Sorcerer's Apprentice
Veteran
Just finished reading 262 pages of this thing.

I'd like to say the following. Reading the actual thread from start to finish is going to answer a lot of your questions. You should do it.

I am going to be adding CMH into my new cabinet design.

I can tell you this much and I've never seen a CMH bulb:

o CMH Bulbs are available up to 400w. No 600 or 1000w are going to be manufactured anytime soon. Quit asking.


o CMH bulbs between 250w and 400w should be run on magnetic HPS ballasts of the same rating. Yes, you can run your 400w CMH on your 430w HPS ballast, but it will shorten the lives of your bulb and ballast.

o Don't use electronic/digital ballasts with a CMH. Only magnetic HPS.

o CMH bulbs at 70w, 100w and 150w operate on pulse-start metal halide ballasts.


o The recommended reflector for 400w CMH bulbs is the Super Sun II, based on Pico's results.


o The Super Sun II will best cover a 2ftx3ft space and can be air cooled to allow you to keep your plant near your canopy.


o You can run a horizontal bulb in a vertical position (or vice versa) but you may shorten the bulbs life and sustained output. This has something to do with the way electricity arcs through the plasma within the bulb. (or something.)

o People who ask questions in the thread usually do so about 2-3 pages after someone just finished answering that question.
 

messn'n'gommin'

ember
Veteran
o CMH Bulbs are available up to 400w. No 600 or 1000w are going to be manufactured anytime soon. Quit asking.


o CMH bulbs between 250w and 400w should be run on magnetic HPS ballasts of the same rating. Yes, you can run your 400w CMH on your 430w HPS ballast, but it will shorten the lives of your bulb and ballast.

o Don't use electronic/digital ballasts with a CMH. Only magnetic HPS.

o CMH bulbs at 70w, 100w and 150w operate on pulse-start metal halide ballasts.


o The recommended reflector for 400w CMH bulbs is the Super Sun II, based on Pico's results.


o The Super Sun II will best cover a 2ftx3ft space and can be air cooled to allow you to keep your plant near your canopy.


o You can run a horizontal bulb in a vertical position (or vice versa) but you may shorten the bulbs life and sustained output. This has something to do with the way electricity arcs through the plasma within the bulb. (or something.)

o People who ask questions in the thread usually do so about 2-3 pages after someone just finished answering that question.

Bumping this to this page.

Points 5 and 6 may lean a bit to the subjective side of things, but that's the nut of it. Maybe MPL will see it and include it on the first post.

lol...The last one may be a new slant on one of Murphy's Laws.
 
Last edited:

headache

New member
Advance Tech is a scammer. He hasn't shipped anything despite 2 emails saying he did. Protect yourself and issue a dispute because you aren't going to get anything from this clown in a timely matter.

To the guys who say he is a one man shop according to his emails he has a full staff.

My guess he is full of sh//!





quote=gardenbug;3953229]Ordered from advanced tech but after a week the tracking info says it still hasn't shipped. Either tracking isn't updating or they are really slow to ship. Think I saw a few other posts about them being slow. The price is good and is supposed to come with a free hps bulb as well, but I can't really recommend them at this point.[/quote]
 

gardenbug

Member
Advance Tech is a scammer. He hasn't shipped anything despite 2 emails saying he did. Protect yourself and issue a dispute because you aren't going to get anything from this clown in a timely matter.

To the guys who say he is a one man shop according to his emails he has a full staff.

My guess he is full of sh//!


I ended up getting mine about 3 weeks after ordering, never got any confirmation email about shipping or anything though. After sending a few emails the tracking number on fedex finally updated. I think they just forgot to ship it for a few weeks. Was here like 3 days later once fedex said it shipped.
 

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