Ceramic Metal Halide Bulbs...for HPS ballasts?

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Originally Posted by MaryLane

Hey Dutch how much heat is your lamp giving off? Is it aircooled? How far can you keep it from your plants?

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1. My setup is in a closet. I pump cool air between the top of the plants and the bottom of the light, 24/7. The air comes from my central heat/ac floor opening, using 6 inch dryer-duct hose. If it gets cold at night, it adds heat. I don't have an exhaust system, it's not nessary in the fall/winter/spring, and I don't try to grow in the summer. The excess heat returns to the H/AC system. I maintain 70-85 degrees and 40-50% humidity.

2. The CMH bulb doesn't throw the heat down like the HPS hortilux bulb. So I can get it closer; say 8-10 inches as opposed to 12-15 for the hortilux. If I hooked up an exhaust system to my lamp housing, I could maybe get closer still. It was an option, I didn't get....:(....should have.

This works great for my small personal grows....:D

Ahh cool. Sounds like a nice set up.

I am trying to decide if I want to throw my CMH 400w in a DIY bake a round cooltube or leave it open. I am doing a barrel style vscrog so the distance to the plants is fixed. Right now I am planning on a 20" diameter screen, which puts the radius at 10". I think I amy do the cooltube and reduce the diameter to maybe 18" or so.

What do you think? I will have plenty of ventilation either way, and my ambients never go above 75F, usually staying around 71F.

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Originally Posted by Dutch Pimp

1. My setup is in a closet. I pump cool air between the top of the plants and the bottom of the light, 24/7. The air comes from my central heat/ac floor opening, using 6 inch dryer-duct hose. If it gets cold at night, it adds heat. I don't have an exhaust system, it's not nessary in the fall/winter/spring, and I don't try to grow in the summer. The excess heat returns to the H/AC system. I maintain 70-85 degrees and 40-50% humidity.

2. The CMH bulb doesn't throw the heat down like the HPS hortilux bulb. So I can get it closer; say 8-10 inches as opposed to 12-15 for the hortilux. If I hooked up an exhaust system to my lamp housing, I could maybe get closer still. It was an option, I didn't get....:(....should have.

This works great for my small personal grows....:D

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Quote:

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Originally Posted by MaryLane

Ahh cool. Sounds like a nice set up.

I am trying to decide if I want to throw my CMH 400w in a DIY bake a round cooltube or leave it open. I am doing a barrel style vscrog so the distance to the plants is fixed. Right now I am planning on a 20" diameter screen, which puts the radius at 10". I think I amy do the cooltube and reduce the diameter to maybe 18" or so.

What do you think? I will have plenty of ventilation either way, and my ambients never go above 75F, usually staying around 71F.

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Hi.

I'm not a light expert or anything, but these bulbs are rated for open fixtures. They have X-amount of Uv block built into the glass bulb. If you need to use a cool tube, select the proper kind of glass tube or you will block too much of the Uv light; which the plants love.

A fixed light distance; is a over-my-head growing style. I adjust my light distance daily...:D...and scrog is too.:) I just let them puppies grow. I have plenty of height distance to work with.

Bottomline: Everbody's grow room is different, so I usually avoid giving advice, but the key is to test everything in advance, I think. Keep temps between light and top of plants around 75-80 degrees; with good air circulation, that is good common advice....enjoy!

The thread about MH in flowering, reminded me that I am at the end of 4 weeks of flowering with the CMH bulb.

2 female white widows under a 400 CMH bulb. Still don't have a digital camera, but went shopping for one today. Maybe after the weekend, I will have some pics available.

Anyways, their 3 foot tall and doing very well. Which is about a foot shorter than the last grow under a 400 HPS Hortilux, everything else is the same; nutes, etc.

I like this bulb.

I'm really thinking of getting just an HPS ballast with a CMH bulb, if I have any doubt about CMH it's in the flowering stage, so let us know how much you got, peace.

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Originally Posted by Indico

I'm really thinking of getting just an HPS ballast with a CMH bulb, if I have any doubt about CMH it's in the flowering stage, so let us know how much you got, peace.

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Yea...that's the $63 question. How does it do in flowering? It does great for 4 weeks. The final 4-5 weeks?...we'll see.

Remember...the CMH bulbs are NOT to be used with digital ballasts...magnetic ballasts only.

Exhibit A. 4 1/2 weeks flowering...(I really should finish painting the walls...:stoned:)

i noticed that you are warning the use of e-ballasts, so I have been lookin around and came up on this

http://www.hydro-techn.com/showcandle/newscan.html

I feel that this bulb will produce more yeald per watt, no? Is your progress anything above average?

Exhibit B...end of 7 weeks flowering.

so is this better than a hortilux?