It depends on the bulb. I kept my 96-W Panasonic bulb for almost 2 years
before replacing it. But the replacement bulb, which was a cheap generic,
only lasted 4 months before the glass cracked. On top of that, the generic
was not very bright to begin with and it lost more light intensity during
the 4 months than the Panasonic during the 2 years. So stick with brand name
bulbs. I believe AH Supplies carries them. They should last at least one
year, but then again, it depends on how much light you're willing to lose.
__
Alex R

"chet" chet-at-surewestDOTnet wrote in message
...
Today I installed an ahsupply 1 x 55 kit. Cool beans. Other than my own
stupidity of trying to install the ballast the first time in a location
where it couldn't possibly fit, all went well. So, how frequently do these
bulbs get changed? Surely not once every 6 months.. I hope.

chet