KenInVic said:

Are you certain you have a dual purpose ballast?  Some ballasts are designed for one lamp type or the other.

If you have a dual service ballast, I would suggest trying a known good lamp in your ballast to make sure it's your lamp and not the ballast.

One other thing, are both lamps the same wattage as the ballast is designed for?

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Stoneth said:

Generally speaking bulbs are recommended to be replaced every 4 to 5 months for best results.

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Quote:

his Optimized Spectrum Metal Halide Grow Lamp allows you to stretch your growing season to 365 days a year. Fine-tune your lighting system to provide optimum spectral energy levels that promote vigorous plant growth. Optimized Spectrum Metal Halide Grow Lamps provide high initial and maintained lumen output with optimum spectral energy required for vegetative growth. Optimized Spectrum Metal Halide Grow Lamps are designed to grow high quality, natural looking plants during all phases of their growth cycles.


1. High output,balanced spectrum is engineered specifically to promote vigorous plant growth.
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3. Optimized spectrum (Violet and Blue) and high PAR (Photosynthetic Active Radiation) to enhance vegetative growth
4. Extra-low lumen depreciation: maintaining over 90% of initial lumen output after running for 5,000 hours.
5. Fusion Bright bulbs work well with both Magnetic and Digital Ballasts.

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