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Lightbulb questions and 'experiment': wattage, spectrum, etc.

Hey kids. It's been a while.

Recently, i've been moving around the light fixtures and bought a GIGANTIC (emphasis on entire word) light fixture from a rather sketchy place nearby for cheap. I think it used to be a pot grow light. Anyways, the thing is really huge; it's a, and i extract from the bulb box the following info,: optiLUME 400 watt metal halide lamp with a concentrated blue-yellow spectrum designed for vegetative growth
Lamp shape: ED37
ANSI ballast: M59
Watts: 400
Temperature: 4,200 K
Initial lumens: 39,000
Life: 10,000 hours
Burn Position: Universal

So, that's the box. No pics yet, but i was wondering if anyone else has done something quite like this. If there is any information on how good this is compared to, say, typical cool white fluorescent tube bulbs, lemme know. I've seen a guy growing plants using something that looked quite a lot like this in Switzerland, and i dare say his plants were mind boggling in beauty and epic splendor. :jester:

PS: I should probably tell you what i'm growing.
i specialize in drosera. Intensely. I want them dripping in dew and crimson red. That's what i love to do. I need something with intense light to grow D. regia, madagascarensis, large red capensis, dichotoma, peltata, etc. If anyone has hunches about this light, or knows a thing or two, i'm listening.
 
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Not sure about the brand, but metal halides are great when working with long distances from bulb to plant. Problem is they put out A LOT of heat and draw a considerable amount of energy.
 
That's good news!
I have the heat and the energy under control, using a computer fan to ventilate and keeping the room cool in general. As a matter of fact, i have the lights set up right now - just wondering if the plants will thrive long term.
 
I sell irrigation supplies and one of the things I can special order is indoor growing supplies (OF COURSE for growing tomatoes and such ;) ). You will get MUCH more in the way of lumens to your CP's using HID than with flouro., including the T-5HO (tho with an 8 or 10 tube fixture you start to come close)! The one thing to be careful of is the heat (HID emits a LOT more heat than other lights) as 31drew31 said, but if you've got that covered, GREAT! As an fyi, the manufacturers usually recommend 80 cfm of air flow for 600w HID in air-cooled fixtures so I'd prolly recommend 50-60 cfm for a 400w.

As far as long term use, these lights still don't hold a candle to the sun, so you should be fine there. Also, the bulbs should be replaced every year or two as they start to drop off in light output, and new bulbs need a "burn-in" period of a week or two where they're pumping out WAY more lumens than spec and then they settle down.
 
Of course! Growing tomatoes.
That's really reassuring; i was a little worried that i'd invested in something that was not of a compatible design; i HAVE put my eggs in one basket.
Posting a pic soon enough here...
 
DSC_3648.jpg

DSC_3647.jpg

Distance from lights to plants is approx 16 inches or 40 cm.
Opinions?
BTW most plants have recently undergone transplant and have been pruned extensively (as i usually do). Species are D. capensis (all forms 'cept Bainskloof), spathulata, madagascarensis, filliformis "red", venusta, regia, dichotoma, binata, multifida, falconeri, dielsiana, nidiformis, and something weird that looks like affinis crossed with a broad capensis.
 
Nice set-up! Only thing I would say is make sure the fan on your fixture is "pulling" the air from the hood... oh wait, is there glass on your fixture (i.e. is it sealed?) or is it open?
 
It's exporting air from the system, and yes, there is glass.
It almost seems dangerous. :laaa:
 
Nah, not dangerous... you should hear some of the install stories I hear :crazy:

I'm quite jealous of your regia btw
 
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i'm sorry you had to see that. it's much smaller now that i've trimmed and transplanted it - it's probably set back a little.
:spider:
ooo! pretty spider.
But really. Does it matter if the glass is open ya think? I hear that these things aren't waterproof, 'specially the bulbs.
 
  • #11
40cm is very close for a 400W fitting, so keep a close eye on the plants for any signs of burning. I would not removed the cover glass if I were you, having seen a MH bulbs 'explode'.
 
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  • #12
Does it matter if the glass is open ya think? I hear that these things aren't waterproof, 'specially the bulbs.

Nah, the glass is there so water doesn't get to the bulb in unsealed fixtures, and to allow air cooling of the fixtures in sealed fixtures (the air generally being exhausted out of the room).

I asked about the glass because if it was an open fixture you'd wanna "push" the air through the fixture, but if the glass is there it's better to "pull" even if the glass isn't "sealed."
 
  • #13
Metal halide bulbs are high pressure. Some cover glasses are provided to act as an extra protection should the bulb fail. There are two common forms of metal halide bulbs, one which is a high pressure lamp within a low pressure envelope (looks like a bulb within a bulb) and the other type doesn't have the low pressure envelope.

http://en.wikipedia.org/wiki/Metal-halide_lamp
 
  • #14
mobile - not sure how it is in Scotland, but here in the U.S. all the horticultural fixtures and lamps are of the single envelope type when it comes to HID (disclaimer: I say "all" but there's probably an exception or two). The fixtures sold here in the states with cover glass are generally for air-cooling the fixtures, the protection of the lamp (bulb) being a byproduct.

That being said... yes, I agree with you, you DON'T want to get water on a hot lamp. I've never seen it but I hear the results are unfortunate :0o:
 
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