Light loss from florescents

>I've got to ask again. Where does this information that bulbs lose 10-20%
>of their light over 6 months come from? I haven't been able to find
>technical charts on any fluorescents that match this claim.
>Greg. Tong
>San Francisco, CA, USA
>gtong at sirius_com

        On 26 May 1995 I installed 4 x 40 watt florescent tubes over my
aquarium. The hour meter read 1786 and according to my Sekonic Lux meter the
light measured 2200 lux. Tonight the hour meter is 3879 (about 168 days,
a little less than 12 hours per day) the lux meter read 1700. This is a loss
of nearly 25%.
        I think it was Karen that said she changed one lamp every 3 months
this is a good idea, it will maintain a high level of light.

Doug Bardell
Garson, Ontario, Canada
home page:http://users.feldspar.com/~dallenb/Welcome.html