A shot of some CMH light...

Thought I'd show off how crisp and nice the CMH lighting is. This is a 400w'er.

As you can see my mothers were just savagely cut back, as they were getting far too bushy in there.

All my plants under the CMH seem very happy and I'm really looking forward to getting my flowering area setup.

If you have any questions about the CMH I'll do my best to answer them, but I don't sell them.

there are several CMH'ers here it is the light I reccommend but it seems to be not as popular here as on other sites

where did you buy the lamp from?

250w cmh is what i have in my veg roomthe cfl's are more for the seedlings

robert 14617 said:

250w cmh is what i have in my veg roomthe cfl's are more for the seedlings

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I find it amazing how dark and beautiful green the leaves get under the CMH. My seedlings that were raised under the CMH went dark green and the ones under the HPS were yellow green. Even my t5 didn't give as nice of coloring.

NavySupra said:

I find it amazing how dark and beautiful green the leaves get under the CMH. My seedlings that were raised under the CMH went dark green and the ones under the HPS were yellow green. Even my t5 didn't give as nice of coloring.

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The light does not effect the plants leaf color, the nutes you feed it/nutes that are in your medium determine it. Plants are looking nice though
You growing in all hydroton?

my walls and door case are white , in the photo you can see they are blue from the light spectrum of the chm great for veg

tom__420 said:

The light does not effect the plants leaf color, the nutes you feed it/nutes that are in your medium determine it. Plants are looking nice though
You growing in all hydroton?

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I would question that position.

50/50 Hyrdoton and promix. 1tsp per gallon of each of a bunch of stuff I got at the store.

I used this exact same combination, and in fact two of the plants in this picture were under the HPS and did not get this green until being placed under the CMH. Could the noticeably higher UV have anything to do with the color change?

I've pulled back the food a bit though as I have noticed the leaf tips getting a little burned.

Yes do you see how you are getting burns? That is because you are feeding the plants a lot of Nitrogen, that is the food that keeps leaves dark green like that
It is the food not the light bro

tom these orange bud have only been fed twice with a 7-7-7 violet food

What point are you trying to make...?
7-7-7 means that 7% of the nutes are Nitrogen meaning it is very high in N
Two feedings would keep them that green although I see some yellowing on the bottom so it may be time to hit them again with food
Do you guys have any info to add or is this all by opinion or just a guess? Stop feeding one of your plants nutes with any nitrogen in them and see how quick the green goes away
The light isn't magical, it doesn't shine nutrients on the plants.... your plants are so dark green because of those home depot nutes your using

tom__420 said:

What point are you trying to make...?
7-7-7 means that 7% of the nutes are Nitrogen meaning it is very high in N
Two feedings would keep them that green although I see some yellowing on the bottom so it may be time to hit them again with food
Do you guys have any info to add or is this all by opinion or just a guess? Stop feeding one of your plants nutes with any nitrogen in them and see how quick the green goes away
The light isn't magical, it doesn't shine nutrients on the plants.... your plants are so dark green because of those home depot nutes your using

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First, I'm using quality nutes, from a local supplier, not Home Depot.

Second, the only variable that has changed is the lamp in the socket. Feeding ratios, watering times are the same as when I was growing under the HPS. They were green, but not like they are now.

Therefore, if the only variable that has changed is the light source, is it not reasonable to accept that as the cause? I'm not saying this lamp is magic, just that my plants are happy and I'm offering up my observations.

http://www.growlightexpress.com/pages/ceramic-metal-halide-pv-c0-2.html


the light spectrum is more favorable for vegetative growth and has higher uv output

First, I was speaking to rob, he stated that the nutes he was using were 7-7-7 violet food which they sell at home depot

Second, if your plants have grown than they have a better root system allowing them to take in more nutes thus being greener

I'm sure your plants are growing better now that they are under the CMH but that CMH bulb does not change the color of the leaves. The only way that it could change the color of the leaves in any way was if you put it very close to the leaves and you bleached them out. Think whatever you want though man, if you want to believe your right than thats just fine with me. Could you just explain how the light would make the plants greener than when you were using different lights?

tom my plants have been in veg 8 weeks now , how could the two feedings of less then 7 drops per liter of water ,twice during two mo. darken my foliage this much and still show signs its needing more feed

robert 14617 said:

tom my plants have been in veg 8 weeks now , how could the two feedings of less then 7 drops per liter of water ,twice during two mo. darken my foliage this much and still show signs its needing more feed

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Nitrogen deficiency starts from the bottom up, you have nothing to worry about yet. Although I would suggest feeding in the next week or so



And yes those bulbs may be more favorable for vegging but that does not mean it will keep the leaves anymore green than another light

While I disagree with the all too prevalent arrogance of Tom's presentation I do agree with what he's saying. I have five young plants all under 2700k cfls. I feed them all the same and the smaller ones are darker green than the larger ones because they really don't need as much food.

Jeez. It's a freaking light. Put your plant under it, grow it, harvest it, and smoke it. Why do people argue so much over light bulbs on this site?

hydgrow said:

where did you buy the lamp from?

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A local speciallized commerical lighting warehouse... The verticals were $57 and my horizontal are $87 becuase they are non-stock items.

Tom, I don't know enough about horticulture to know if it is food or light that changed the leaf color, the only thing I know for certain is that I only changed one variable in my setup.

I have read that the spectrum this light offers increases root developement in the plants which would explain a higher intake of nutrients and possibly nitrogen as you say, but then if that is true it is still the light that is responsible for the change in leaf color.

Some of the leafs under my cmh turn purple and i think its from the light.

i am very interested in these bulbs . they run in a standard hps.. now is this just a conversion bulb? what is the lumen difference in this and a standard?
i havean xtra 400 watt hps ballast and would love to throw some xtra blue into my veg tent.
is this better than a 400w mh?