How long does a PC bulb "last"

[murgus]

How long does a PC bulb "last", that is, how long until there is too much drop off in intensity?

Andrew

[BigDaddy]

Until it burns out.

Compact fluorescent bulbs (aka power compacts) are unlike normal fluorescent bulbs in that respect.  While a normal fluorescent bulb will change its intensity over time due to the design of the unit, compact fluorescents do not.  Most compact fluorescent bulbs (and some T8's and T5's) use triphosphor technology.  One of the benefits of their design is that their spectral output goes relatively unchanged over the entire course of their life, compared to the very large changes in spectral output of NO and VHO bulbs.

[murgus]

Until it burns out.

Compact fluorescent bulbs (aka power compacts) are unlike normal fluorescent bulbs in that respect.  While a normal fluorescent bulb will change its intensity over time due to the design of the unit, compact fluorescents do not.  Most compact fluorescent bulbs (and some T8's and T5's) use triphosphor technology.  One of the benefits of their design is that their spectral output goes relatively unchanged over the entire course of their life, compared to the very large changes in spectral output of NO and VHO bulbs.

Thanks BD - I just picked up a used 24" Coralife and was wondering about the bulb that was in it - didn't seem much brighter over the tank than the 30" of NO T8 I had on it before (the PC is 65W).

Andrew

[BigDaddy]

Ensure the bulb is also Coralife... there are some cheap "replacements" out there that are very poorly designed.

[murgus]

Ensure the bulb is also Coralife... there are some cheap "replacements" out there that are very poorly designed.

Yup - the bulb is coralife.  I guess I just expected 65W to blind me when I looked at it - lol.

Andrew

[Seanc]

I have the same thing as you. and man is it alot brighter then my NO tube. if you take it off the tank and look at an no tube then the 65watt, man is it ever different. But i agree it doesn't look that much different then my no tube when you see it inside the tank.

thats good to know BD i like not having to replace it when it gets 6 mths

[Julie]

My 65 watt actinic changed spectrum at 9 months and I believe it was partly responsible for cyanobacteria in the front of my tank, specifically below the actinic bulb.

I noticed when I changed the bulb what a difference the new bulb made in the colour of the tank.

[BigDaddy]

I'm pretty sure an actinic bulb doesn't use triphosphors.  Good call on that Julie, CF Actinics would be the exception to the rule.

[murgus]

I'm pretty sure an actinic bulb doesn't use triphosphors.  Good call on that Julie, CF Actinics would be the exception to the rule.

Ah, that might be it, the bulb is 50/50.  Perhaps the actinic "side" is fading a bit.

Andrew