Light Numbers: FYI

[Palmer]

Out of curiosity how old were the bulbs? I know you said each fixture is about a year old does that include the bulbs?

[fencer]

The bulbs are 1yr old and will be changed out next month. When new i was only getting about 20% more LUX on average

[Palmer]

I am no lighting expert but just for fun i was looking at lumen maintenance (apparently a measure of a lamps lumen output over time) of MH verses T5. The T5 looked about 95% at 20,000 hours of use-

http://www.lrc.rpi.edu/programs/nlpi...s/lat5/pc9.asp

and

Metal halides lumen maintenance appear to be much lower- http://www.lrc.rpi.edu/programs/nlpi...teristics2.asp

This is probably a nice bonus for T5 and perhaps something to consider when evaluating the Lux performace of T5 and MH on your system when at 1 year of existing use?

Although maybe I am completely wrong as i am no engineer!

[fencer]

I will let you know when I replace the bulbs