Ceramic Metal Halides

So I've been reading dozens of pages from the ICmag forums about CMH's. Has anyone grown with these?

I was going to get a 600watt HPS but after reading about the CMH's I'm considering just using a 400watt CMH instead. I figure I can light the same area (due to the light spectrum efficiency giving what I would assume to be about the same lumens to the plants) and also hopefully get slightly denser buds. I think the main reason CMH's give denser buds is because the spectrum gives so many lumens to the plants that they don't need to stretch(same way putting a light closer to the plant gives more lumens = less stretch). I mostly want to do this so that I can get a bunch of root growth on very healthy clones to flower faster while also saving some electricity costs.

Has anyone used a 400watt CMH as opposed to a 600watt HPS and noticed any differences?

Good for you looking at CMH but actually the lumenes are a bit less and DO NOT matter, it is the SPD and PAR of the CMH thast make it a better light for our babies (plus has UVB)

and there is a grow on here look for "welcome to the jungle" in the grow journal forum

I am currently doing an experiment to show a way to flower with just one 65 watt cfl once it is done my next experiment will be with CMH

The Rev from Skunk magazine raved about CMH bulbs....until he tried them. Then his position was quite different.

The total lumens are less but the lumens in the wavelengths we need are a higher %. The question is does the 400watt CMH have enough lumens in the wavelengths we need, to compare to a 600 watt HPS. The 600watt hps has about 3x as many lumens as the CMH's. However, the CMH's have about 3x more of their light in the wavelengths we need. In the end, I'm just not sure if it's still worth getting a lower wattage CMH even though their lumens are put to better use. There is no doubt that a 400watt CMH outdoes a 400watt HPS.... but a 600 watt HPS is more efficient for lumens (and lumens in the red wavelength that we need).

As I said... the ridiculous root growth might still make the sale for me. I have some daylight t5 Fluorescents that I can use with a 600watt HPS for added blue... but I also have a 150watt HPS to use with the CMH for added red. I think the 600watt HPS will be the way to go if I want some bulk (with daylight fluorescents assisting the blue spectrum) because even with the 150watt HPS the CMH's just might not have enough red. This is why I'm asking if anyone has used the 400watt CMH's and preferred it over a 600watt HPS.

https://www.rollitup.org/grow-journals/210479-dual-areoponic-cabinet-ceramic-metal.html

Cruzer101, he'd be the one to ask. i am thinking about trying a cmh in my 250. i find that growers on this forum are not adventurous or want to try things that are too new.

that and the bulbs are about twice as expensive as hps

they are 50$.... HPS is the same

My hps was $21 the Cheapest i could find a cmh is $52. I am waiting for cruzer to finish his hps grow and see what he has to say. but i am seriously looking at the cmh. The thing to remember is Lumens are a unit of measure developed by and for HUMANS. It is a good rule of thumb but it favors an area of the color spectrum. PLANTS are NOT HUMANS, they all have different needs. I know that was a duh statement. The real question for us here at this forum is does the shifted spectrum help hinder or do nothing for cannabis. I mean look at leds they are awesome if you are running them off of solar panels but if you are looking for fat dense nuggs... well you might need to look elsewhere. The Ceramic metal halide is just to god damned new most hydro shops havent heard of them let alone what their performance is.
Lets face it no one wants to spend 50-100 bucks and waste 2 months on something that might reduce their output.

I am wondering if the superior spectrum alone can make up for the loss in Lumens. Something to think about - if it is just about the spectrum, why not use incandescent bulbs with a CRI of 100? Or, how about CFLs? Don't they have a superior spectrum as well?

I think somewhere there is a balance between spectrum and sheer Lumen output and our job is to find it. A 600W HPS puts out 90,000 Lumens while a 400W CMH, 34,800. So, the HPS puts out 2.58 times as much light. Or, you would need to burn 2.58 as much power. So, I guess the question is if the CMH gives double the amount of reds and blues as the HPS.

If you look at the light spectrum of the HPS and pictured the reds and blues being 2.58 times higher you might be looking at a profile not too far off from that of the CMH. Run a HPS and a 6300K blue MH and you have a pretty full spectrum.

Although the CMHs look great, I wonder if their low Lumen output isn't too costly.

I've just decided to give it a try. There's not much info out there so I figured there's only 1 way to know for sure.
I already use blue light in flowering and think it improves plants a lot, so cmh means I can do it with 1 bulb.
If I'm not happy I can just swap out the bulb for a sodium so it's only a £25 experiment.

I'd love to try the CMH also but you need a standard, non switchable HPS ballast and the digital ballasts use about 8% less power.

I'd like to find out what percentage of a CMH's light is in the 400nm - 700nm range as that is where it matters. A standard HPS is about 40% in that range and a blue maybe a bit higher. Not sure where a super blue MH stands. Maybe we could write the manufacturer.

v12xjs said:

I've just decided to give it a try. There's not much info out there so I figured there's only 1 way to know for sure.
I already use blue light in flowering and think it improves plants a lot, so cmh means I can do it with 1 bulb.
If I'm not happy I can just swap out the bulb for a sodium so it's only a £25 experiment.

Click to expand...

What wattage light are you using? Aren't you growing in a computer tower?

It's a pc yes but that doesn't seem to be a problem so far.
The ballast is 100w, the bulb hasn't arrived yet so I don't know the spec for sure but I asked for 3000k as I run a perpetual 12/12.

How much wattage are you running in there now if you don't mind me asking?
Are you going to upgrade the ventilation for the CMH?

Got 162w ATM but it's too much, it's bleaching them a lot. There's 150w red + 12w blue in 1.5cu ft.
I have to change things but I'll be sad because the oil production is phenomenal right now

It will be much better with the CMH bro, have you seen cruzer101's CMH grow on here?
Here is a link: https://www.rollitup.org/grow-journals/210479-dual-areoponic-cabinet-ceramic-metal.html

Go to the last couple pages to see the results, some real sticky shit

Appreciate the link. I read every word, very inspirational.
1 of the reasons ?I chose the bulb.

This is not a new bulb, has been around for years, there is a thread on another forum that was started in 07 and is still going, lot's of testing, comparing. If your thinking CMH it is a must read, if you Google "Ceramic Metal Halide" it will come up.

Once you read that thread you will know that is "ONE" bulb that is better the attached pic is the spectrum of that bulb compared to HPS

The buds are not necessarily bigger, but are ALWAYS better in every CMH grow I have seen, thoughts are the UVB is what causes this.

The main reason that CMH has not "caught" on is the restrictions MUST have old magnetic ballast and only available in 250 and 400 watts

Also there are no heat problems, there is a pic of a guy actually holding the bulb while it is on in that thread (try that with HPS)

If you are interested in a personal, medical grow CMH is Da way to go!!!

The CMH actually compair well to the Eye blue MH bulbs in lumen output. And using many 400W bulbs as opposed to a single 1000W gives far better coverage. The down side is the initial cost of more fixtures.

I think I will try using these for my next setup.