Change Compact Florecent How Often?
- Thread starter knashash
- Start date
If you dont see any decrease in your plant performance, dont change them . If it aint broke, why fix it?
In the December issue of FRESHWATER AND MARINE AQUARIUM I read some good information concerning fluorescent lamp longevity. The author's name is Kevin Osborne. The following is directly from the article.
According to the article, the rated life of the fluorescent lamp is exceptionally high. If your using a standard output full-spectrum tube, it is typically 20,000 hours, established by lamp manufacturers through "life testing." The author of the article states that he rarely changes his standard output lamps before five years. He based this on a daily photoperiod of 9-12 hours, which was still well under 20,000 hours.
What about photo depreciation and spectral shift? The normal lumen depreciation---20% for standard output tubes and 40% for VHO---levels off after the first year of usage, and plants don't care about lumens anyway. The lumen is a measure of brightness to the human eye.
As to any other spectral shift, it is minimal and would also level off after the first 12 months. In any case, if output depreciation were a concern, it would be better initially to oversize the lighting system to compensate, rather than discarding tubes after 6 months or a year, or even 2 years. Thanks to electronic ballasts, output depreciation of the fluorescent lamp no longer needs to be a concern.
According to the article, the rated life of the fluorescent lamp is exceptionally high. If your using a standard output full-spectrum tube, it is typically 20,000 hours, established by lamp manufacturers through "life testing." The author of the article states that he rarely changes his standard output lamps before five years. He based this on a daily photoperiod of 9-12 hours, which was still well under 20,000 hours.
What about photo depreciation and spectral shift? The normal lumen depreciation---20% for standard output tubes and 40% for VHO---levels off after the first year of usage, and plants don't care about lumens anyway. The lumen is a measure of brightness to the human eye.
As to any other spectral shift, it is minimal and would also level off after the first 12 months. In any case, if output depreciation were a concern, it would be better initially to oversize the lighting system to compensate, rather than discarding tubes after 6 months or a year, or even 2 years. Thanks to electronic ballasts, output depreciation of the fluorescent lamp no longer needs to be a concern.
Does high bulb temperature accelerate the deteriorization process? My Coralife 28 watt CF fixture is the smaller one that doesn't have fans and it gets warm enough to keep the tank at 75 degrees without a heater. I have considdered getting the clips to stand it up off the tank to keep it cooler. I was just looking at the light today thinking it's gotten dimmer since I bought it a month ago. The bulb was new then, and it was so bright it hurt to look at. Is there some kind of initial break-in period where they get slightly dimmer early in their life, but then roughly stablize?
Thanks.
Thanks.