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View Full Version : Does this bulb need replacing?


corbett_n
02/04/2010, 09:04 AM
I got this metal halide bulb from a guy who said it was only three months old, what do you think? I was worried about the black around the edges.
http://i161.photobucket.com/albums/t219/corbett_n/DSC00217.jpg

spleify
02/04/2010, 09:59 AM
Unfortunately with used bulbs you have to trust the source and take there word for it. Burn in happens quite quickly on MH bulbs. IME, that bulb does not look that old, but as mentioned you can tell it is used. Some of the "burn in" will get "blacker" as they get older.

HTH, and makes sense

corbett_n
02/04/2010, 10:11 AM
thanks

spleify
02/04/2010, 10:14 AM
:thumbsup:

No problem your welcome

thegrun
02/04/2010, 10:15 AM
The burn marks don't tell much, other than the fact that it has been used. MH bulbs lose 25% or so of their total output in the first 3-4 months and then gradually decline after that. I replace mine every 12 months, but in reality if you went a couple of months longer there will not be much more of a decline. A sudden increase of algae growth is often a sign that the bulb should be replaced. In your case it come down to how much trust you have in the seller.