Ceramic Metal Halide (CMH)

[Drek]

Hmm. I'm slightly skeptical (and not because I just bought a bunch of them at discount prices

). The energy output per watt (efficiency) statistic I was already aware of.
Theoretically (spectral), there shouldn't be that much of a difference between them.

The spectrum of the Retro White is exceptionally even across all wavelengths, and at 4k, is still pretty healthy in the upper wavelengths.. ~ 600-700nM. It almost seems like it should be around a 3800-3900k lamp.

To me, it looks like it would be more or less splitting hairs between the two at 4k, with the Retro having slightly higher relative energy output. Albeit, being less efficient and slightly hotter.

Either way, they're both Mastercolor CMH lamps, so the spectral similarities aren't (shouldn't be) surprising. It basically resembles (to me) a repackaged Retro White with a better ballast...which would make sense as the Retro is the immediate predecessor.

Another big benefit for me, is the open enclosure rating. I'm not really sure if I want glass between the lamp and the plants, with the lamp being cool enough in that application, and it saves my costs
in purchasing a fancy hood. As far as hoods go, I think I'll eventually pick up one of the Bell LR-400's.

 

[rives]

Azeotrope has a pretty serious electrical background, and had been using the 400w CMH for several years. He swapped over to the 315 and was amazed at the difference - same strain he'd been growing, same setup, etc.

If you take a close look at the SPD charts for each of them, I think that you will find that there is a great deal more red between 600-650 on the 315. I think that either of them will do a good job for you, but I think the 315 has a significant edge. It seems comparable to the variations of the HPS lamps to me - minor adjustments in the bulb makeup can create a pretty significant difference in the spectrum and change it from a basic industrial lamp to something much better suited to horticulture.

*edit* - Depending on your usage, you would be fine with either. For instance, I'm just a personal grower, and while the Agro should have a pretty serious advantage over the standard 930, I can't justify changing over at this point. I've got a case and a half of the 930s which I paid $20 a lamp for. I have one Agro that I've used for a couple of runs, and it works great, but I''m about to harvest what appears to be the best gpw run that I've ever made and it was done with the 930s. I haven't had the opportunity to do a side-by-side, so a direct comparison is impossible, but the 930s work very, very well. In your case, with the ballast losses, you are giving up about 30% on power usage and perhaps some yield. 30% on the power sounds like a lot, but per lamp it only works out to roughly 1.2kw/day. Unless you are running a bunch of them, it probably comes down to a few bucks a month and a few grams of pot. It would be very interesting to see a direct comparison, though.

400w Retro-White -

315w CDM 930 -

315w CDM Agro -

 

[Drek]

I've learned to take people's subjective opinions with a grain of salt, because people tend to convince themselves of things for a lot of different reasons. I like to stick to science and facts; more or less, remaining objective.

It's the only way to weed out bullshit from the truth.

I was comparing mainly the Retro and normal 4k CDM. Retro appears to be a little stronger in the 400nM and 650-700nM range with the CDM slightly higher at ~ 600nM. The difference wouldn't be enough to swap everything out, for me, and from the graph I think I might almost slightly prefer the Retro. Again, splitting hairs. It's tough to go off graphs alone tho...

The 3k Agro is going to be more red at 3100k. It looks to have a little more of an overall balanced average as far as PAR goes, which makes sense being Agro.

We'll see how my current 4k grow ends up. So far pretty good.

 

[jorgeblen]

What do you guys know about it? Will that be worldwide or only in europe?
This is a recent publication of a major hydroponic supplier in the UK.

Cheers

 

[Drek]

I actually entertained that thought not too long ago, of Philips backing out of the Horti market all together.

Hmph. Not sure what to think. If I read it literally, it doesn't say that they're withdrawing their Horti products from the commercial marketplace (in whichever country).

 

[RikkiTikkiTavi]

A CDM lamp is a CMH lamp.

I can't see there being much difference between the two other than availability and efficiency, in which the CDM would be better.

Philips Metal halides (and a few others) in general @ 3-4k will be fairly close if not identical in terms of their PAR performance and intensity.

http://en.wikipedia.org/wiki/Ceramic_discharge_metal-halide_lamp

thats like saying all HPS bulbs, or all florecent tubes are the same. just not the case.

 

[reents0]

A flood light is going to concentrate the light too much at the distances that you are going to be working with. Try and find "low bay" fixtures - they are designed to spread the light over a much larger area.

I installed the light, and it worked, for once, and stopped working.

As soon as I turn the ballast on, the bulb flashes brightly for an instant and makes a ticking sound. And then it goes dark, as though it was never turned on. If I leave the ballast on, the bulb will continue to flash every few minutes, but never retain any light after the flash, none at all.

Neither the diagram of the ballast nor that of the bulb indicate anode and cathode, so I just plugged the wires in randomly. The diagram of the ballast did indicate ground though.

Did I do something wrong or is the bulb broken?

 

[RikkiTikkiTavi]

thats like saying all HPS bulbs, or all florecent tubes are the same. just not the case.

thats an oversimplification, but even when discussing bulbs from the same family it holds true imo.

 

[Drek]

Thanks for your reply.

http://en.wikipedia.org/wiki/Ceramic_discharge_metal-halide_lamp

 

[Stoogots]

overgrow.nl...but u can ask a the ic members stoogots or pasqn

Why do you speak in my stead? Why don't you share your knowledge?

 

[reents0]

I installed the light, and it worked, for once, and stopped working.

As soon as I turn the ballast on, the bulb flashes brightly for an instant and makes a ticking sound. And then it goes dark, as though it was never turned on. If I leave the ballast on, the bulb will continue to flash every few minutes, but never retain any light after the flash, none at all.

Neither the diagram of the ballast nor that of the bulb indicate anode and cathode, so I just plugged the wires in randomly. The diagram of the ballast did indicate ground though.

Did I do something wrong or is the bulb broken?

I think now I shorted and burnt the bulb. I tried again and the bulb shined brightly for several seconds and went dark. The arc is now complete black(not the outer glass). Now, when I turn the ballast on, the bulb flashes a faint blue light for an instant.

 

[Jhhnn]

Received six cmh330 bulbs from the vendor mentioned in post 6020. USPS really hammered the package. One bulb had visible separation of the internal metal conductor rods, 2 others acted almost like strobes when warmed up. Should have played some Jefferson Airplane to complete the effect. I shut them down rather quickly, figuring I didn't want to test their open fixture rating. Vendor to re-ship, seems very stand-up so far.

The visual impression of the spectrum is on the golden side of sunshine, much like my dual arc. Intensity at the very small arc is very high- just glanced at it directly, a mistake, as I saw spots for awhile.

Switching to this bulb for some AF sprouts. It's a seed run for outdoor container gardener friends & other Coloradans who want 'em.

I harvested 450g of dried bud from the last run, curing now, so stash isn't an issue. After my scheduled mechanical rework, the next couple of runs are for seed. I have a couple of growshop contacts who'll give 'em out like candy on Halloween.

Seeds are the bottleneck to more widespread personal growing in CO, and I want to change that in my own small way. Kinda miss seeded bud, anyway.

 

[Drek]

The visual impression of the spectrum is on the golden side of sunshine, much like my dual arc. Intensity at the very small arc is very high- just glanced at it directly, a mistake, as I saw spots for awhile.

Essentially, full sunshine nearing the end of summer. I made the same mistake and looked at arc tube when I first fired my CMH up. Now I don't do that anymore. I keep a pair of sunglasses on the hood that I use when I think I need to.

Kinda miss seeded bud, anyway.

So do I. Some of the best weed I've ever smoked in my life had seeds. I'm sure I'm not the only one!

 

[e_24]

So thy make any other color temp then 4k for the 330w? All I'm seeing is 4k, and a 3900.

 

[Jhhnn]

So thy make any other color temp then 4k for the 330w? All I'm seeing is 4k, and a 3900.

I only know of the 4K version. Other light sources with slightly different spectrums may give slightly better yield or whatever, but I figure they'll do the job just fine. I'll try 'em for veg, first, then add 'em as supplement to my dual arc if I can dissipate the extra heat.

 

[e_24]

Before I throw a few bucks at this equipment which wil be great, no doubt, but I'm more concerned with finding a reflector to spread the light. I have a hydrofarm reflector that fits in my 20x36 tent, but it's so old and slightly inefficient at spreading the light. It has a kinda shiny aluminum reflector inside, with three available ducts for air cooling that can be blocked off if I only use two or even one. I'm thinking something that I can place length wise in the ten with the bulb going front to back. I have yet to find a reflector of the correct dimensions and bulb placement that would bet suit my tent.

 

[e_24]

Sorry for the double post, but I had to add, but the only setup that will give light to all corners and be in th under 400w range, is a 300w induction light which measures 36x17, perfect for my tent dimensions. I'm not trying to get into industion yet so this is a moot point.

 

[Drek]

The Bell reflectors look nice. ie: The reflective coating that they use.

http://www.belllighting.com/

 

[nr nodes]

For those interested in higher wattage, you might consider these. I am testing one in my veg room now, and the results look very promising. They have both open and enclosed BU lamps, as well as an HOR version (which like all metal halides, is rated for shorter life than when hung vert).

http://www.venturelighting.com/LampsHTMLDocuments/Uni-Form_775W_lamps.html#775W

This is the one I have: http://www.venturelighting.com/LampsDataSheets/NaturalWhite/24983m.pdf

 

[staank]

If you dont mind, where did you order from? and what was the cost?

For those interested in higher wattage, you might consider these. I am testing one in my veg room now, and the results look very promising. They have both open and enclosed BU lamps, as well as an HOR version (which like all metal halides, is rated for shorter life than when hung vert).

http://www.venturelighting.com/LampsHTMLDocuments/Uni-Form_775W_lamps.html#775W

This is the one I have: http://www.venturelighting.com/LampsDataSheets/NaturalWhite/24983m.pdf