I think most of us know that the regular fluorescents need to be replaced every 6-12 months due to spectrum shift. At what point do Compact Fluorescents need to be replaced?
I've heard that they can be run until they burn out, but I've also heard that they do suffer from some degradation and should be replaced earlier. I'm wondering if older bulbs might be a part of the algae problems that I've been dealing with in a couple of my tanks. The bulbs over one tank are 12 months old and the bulbs over another tank are 1 year and 8 months old.
I've seen this question asked several times, and also seen various answers. So, I went ahead and emailed Coralife to find out when the bulbs should be replaced. Here's what I recieved:
It actually depends on the plant species. You can go as long as 16 months for some species, and as little as 6 months for more sensitive species. On average if you change them out every 8 to 10 months you will be good.
Product Lines Tech. Support Dpt.
I'm glad this topic came up again...I started my 10 gallon tank in July 2006 and I was just thinking about when the bulb should be changed. I'll make a note in my tank log to order a new bulb in the next month or two.
I just changed mine, after 2 years (4 x 96W, ouch$$).
I changed only half of them at first, to watch them side by side, man, what a difference!!!
The new ones were so bright you hardly can stand looking at them!
I actually already had the replacement bulbs on hand, so based on everyone's input I went ahead and replaced them. I really haven't noticed that much difference in how bright the tanks look, but I must say that the old bulbs definately looked as if they'd seen better days. Hopefully soon I'll see some improvements as a result.
I'm currently planning to start replacing the bulbs on an annual basis, since that seems to be the consensus. Added a spot to my Spreadsheet that tracks maintenance so I know at a glance the last time the bulb was replaced.