First Patented in the 1890's Nikola Tesla: A light designed to operate for up to 25 years without a bulb replacement. Inda-Gro, the most advanced form of modern Induction grow lighting, has a 10 year or 60,000 hour warranty, you can expect to use these very effectively for 70,000 hours, with little fall off in intensity of light output or spectrum slump during that period.
Many who are successful with indoor grow lights maintain maximum productivity by replacing their bulbs at least twice a year, if one uses bulbs for grow and bulbs for flower that means as many as four bulbs per fixture, per year.
Enlightened shops and distributors sell Inda-Gro Lights, as well as all the others, the rest may rely soley on selling bulbs over and over and over again for all of the years you stick with HID, CFL, T-8's or T-5's.
On this basis alone, not replacing tubes, one can see that our Inda-Gro Lights will pay for themselves in a shorter run, and will, over the long run, provide a return on your investment multiple times the original investment, based on bulb replacement alone. Add on the potential for energy savings for the lights and some for AC, add price inflation of bulbs and electricity bills, and the return on your investment become greater as the years progress.
The upshot of all this is that with broad spectrum lighting, with the appropriate trigger points for productivity in place, a greater vibrancy is seen in plants, with less health issues, less powdering mildew problems, and with many species higher yields are also experienced, with greater production of Essential Oils.
Even inexperienced growers get great results on the first and second harvests with Inda-Gro Lights. After several generations of cloning and/or seed development your plants species will fully adjust to these lights, with increased yields and enhanced quality.