PC bulb question

[Oafboy182]

I read over in the planted tanks forum (considering ditching my chiclids for a planted tank) that PC bulbs are good untill they go out, because the gases inside don't break down. Over in this forum I've read they are only good for 6-9 monthes. What is the truth about PC bulbs? I would like to know since I use them on both my tanks and don't want to be buying new bulbs all the time if it is not necessary. Thanks for any info.

Justin

 

[Bearfan]

I do mine every 12 months in my planted and 9 months in my reef and do notice a significant increase in growth when I replace them in both tanks.l

 

[fishfreek]

Replace them every 9 months I do. I have had this arguement with FW folks before whom insist that PC bulbs just dont wear out and I have given up as its a lose lose situation. Both parties know they are right and that never works out good.

In the saltwater world there is a noticable difference between bulbs that are 9 months old and new bulbs over a tank. The higher K bulbs will slowly fade into lower K spectirum of light output as the bulbs age.

If you doubt their has been a noticable change I suggest the following. If your tank has bulbs that are side by side I suggest changing out one with a new bulb of the same K rating as the old bulbs. Then look at the tank with one side having anew bulb and one side having an old bulb. If you dont have that ability then I would take a photo of the tank with the old bulbs and then take a photo fo the tank with the new bulbs. Preset the white balance with the old bulbs and I suspect you will be amased at the differences between the two images that would have only been taken moments apart.

 

[Oafboy182]

Thanks for the info. I have a new fixture coming any day now and will do a comparison test. I am curious to see the results.

 

[greenmaji]

e-bay is selling CF bulbs for real cheap if you get 6 at a time.. like around $5 a bulb.. I think its safe to change your bulbs out now if cost is what was stopping foks before..

 

[malkore]

Here's the situation:
in a FW planted tank, the spectrum degradation isn't that bad...the plants still get what they need, until the bulb stops working.

in a SW reef tank, the organisms are MUCH more sensitive to loss of spectrum, and after 9-12 months, its to the point it has a negative impact on the ones that need good lighting. You wouldn't see problems with low light inverts like mushrooms...but stoney corals, and anemones would surely feel it, and you'd start seeing an increase in algae in the tank, as it's far more opportunistic about it's lighting needes.

So really, BOTH sides are right...but they're comparing apples to oranges.