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3/13/2003 9:48:00 AM
Do conversion bulbs lose lumens?

I looked at a conversion bulb for my 400W MH at the local hydro store, and the clerk said the proper bulb was 370(?) watt HPS equivilent. She also said I would lose lumens with a conversion bulb, but don't HPS bulbs create more lumens per watt?

Would an HPS converting to MH also be less efficient?

What percentage of the light is lost?

thank you
The Green Thumbs
3/14/2003 11:29:00 PM
Re: Do conversion bulbs lose lumens?

Here are the numbers for you:
Lumen output for a 360w conversion bulb: around 45,000
Lumen output for a true HPS bulb: around 50,000

Most people use conversion bulbs because of the cost factor. To use a true HPS bulb, you have to have an HPS ballast. With a conversion bulb, you can still use the same ballast, and achieve an HPS light spectrum.

When using a conversion bulb, you are also not getting a "true" HPS spectrum, you are getting as best as you can with an MH ballast. That is also the other thing to consider. I don't know what the spectrum analysis is, but I know they are not the same.
3/25/2003 11:39:00 AM
Re: Do conversion bulbs lose lumens?

Do you know how Mercury Vapor lights compare in, terms of spectrum, with MH? I've heard that they emit from the blueish spectrum but they look kind of yellow.
The Green Thumbs
3/25/2003 10:55:00 PM
Re: Do conversion bulbs lose lumens?

Mercury Vapor lights emit in the blue/green spectrum, but it is a very narrow portion. Definitely not suited for plant growth, mercury vapor lights have the least efficient lumen-to-watt ratio of any HID light (along with the too narrow spectrum they emit). If you are thinking about using mercury vapor lights, I highly suggest against it.
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