Hi Bill,

What I have read is that after the intial drop off (all lighting does
this BTW), they stay relatively constant in their output until they
fail. There are people on the Aquatic Plants list that use them until
they don't light anymore. There is even one plant guru, Tom Barr, who
will take ALL CFs that people are tossing that still work even if they
are a couple of years old! Of course you could relamp every year, but
why would you if they still do the job?

It's hard to get used to the idea of not relamping every 6-12 months.
That was one of the factors that swayed me to the CF side, relamping 4
T12's at $7-10/each twice a year was getting pretty expensive. The
fact they use 1/3 less electricity, well that was the icing on the
cake. Relamping every 6-12 months is good practice with T8s and T12s,
but NOT necessary with the setups from AH Supply. I am still getting
great plant growth, even light hungry plants do well. If you are
growing plants with lower light requirements, like Java Fern or Val,
then it's really not necessary.

Lilly

"Bill Stock" wrote in message ...
I have the AHSupply kit too ( 4x36). Although the bulbs may still be working
four years later, I don't believe they have the same light output. Since the
output decreased gradually, you probably did not notice. I believe the
recommendation is to change your bulbs about once a year.