lightbulb lifespan and issues?

ccLansman

Guru Class Expert
Jan 22, 2008
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Vista, Ca
Just wanted to check, i have had a set of CF bulbs for over a year now and they are starting to turn brown on the plastic part and the light is a lot duller then it used to be. As the bulbs get older do they become less effective? Is it bad to have old CF bulbs? I don't really have an algae problem anymore but have heard that old bulbs can lead to increased algae growth, any truth to this?
 

tedr108

Lifetime Charter Member
Lifetime Member
Nov 21, 2007
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Los Angeles, CA
I have read in several places that yearly replacement of bulbs is recommended. A bulb's effectiveness decreases before the bulb burns out completely, so I wouldn't wait for that.

If the decreased bulb effectiveness hampered plant growth, I guess it's possible that algae could benefit from that.
 

Mooner

Lifetime Charter Member
Lifetime Member
Jun 9, 2006
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Colorado
I've seen PC's diminish as early as six months (PAR readings)(anyone else tracking their lighting?). I've also ran them for a year and up to complete burn out. IME the tanks adjust to the lower light levels/slower growth. One things for sure, when you replace these old bulbs the system will go through a shock (ie more intense light/new bulbs)
 

Gerryd

Plant Guru Team
Lifetime Member
Sep 23, 2007
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South Florida
Hi,

No matter what type of lighting I used, I replaced my bulbs between 6-12 months old at most.

When I used normal flouros, every 6 months.

That way there is not as much variation in the growth due to the diminished light.

I would definitely replace them and expect to increase c02/nutrients in response to the increased light.