Rex: "Consider that you can pretty much run the PC bulbs till they die."
Really? I had always thought that *all* flourescents loose much of their efficiency (for plant growth at least) after 6 to 9 months.
I don't have PCs but use T8s and I change them out every 6 months. Am I overdoing it?
Would love to hear that I am!

Gets expensive changing so often!