How long do CFL bulbs last?

[amy]

I'm thinking about doing a planted tank and looking into lighting options, including calculating consumables.

How long are CFL bulbs good for in a lightly to moderately planted tank?

For that matter, how long do the CF bulbs on commercially available lighting solutions last?

Thanks...

[BoredAgain]

The ones I have are rated for 9 years.

http://img174.imageshack.us/img174/7107/161167nz7.jpg

[Bk718]

The ones I have are rated for 9 years.

http://img174.imageshack.us/img174/7107/161167nz7.jpg

but would be best to replace them atleast after 1-2yrs

[BoredAgain]

but would be best to replace them atleast after 1-2yrs
For normal use, no, for growing plants, yes. :)

[Mgamer20o0]

reg cf bulbs for tanks go out after a year or so. i am not really sure if the light out put goes down or what. this is def one that needs to be tested.

[Fishy_Fun]

i would change them after a year like stated above.as they won't be good for growing plants you can use them around the house though

[jmhart]

i would change them after a year like stated above.as they won't be good for growing plants you can use them around the house though



They are still perfectly fine for growing plants....the plants will just grow slower :). Their output decreases, so your tank wil drop from a very high light tank, to a high, to a medium-high, to medium....you get the idea. As the bulbs age, you can either replace them or add less nutrients. If you are dosing EI and testing nitrate before a water change, as the bulbs age you'll slowly start to notice that there is more nitrate left in the water by the time your water change comes around. This is your sign that your bulbs are aging.