Not All Grow Lights Are Equal: Choose the Right HID for Your Hydroponics

Hydroponics demands great light. Most growers choose HID (High-Intensity Discharge)—but five types exist, and only two belong in your garden.

The Two That Matter

Metal Halide (Blue Spectrum)

• Electricity arcs through metal halides + mercury + argon gas.
• Metal halides tune color temperature and intensity.
• Quartz arc tube, tungsten electrodes.
• Requires electrical ballast; dimmable with matched digital ballasts.
• Growers love the precise color control.

High-Pressure Sodium / HPS (Red Spectrum)

• Sodium vapor produces red light.
• Alumina arc tube (diffused aluminum oxide) handles intense chemical activity.
• Also requires ballast.

Why Use Both

• Metal Halide: Blue light drives vegetative growth—strong stems, lush leaves.
• HPS: Red light triggers flowering/fruiting—tomatoes, peppers, blooms.

Run Metal Halide early, switch to HPS (or run both) for full-cycle photosynthesis. Inferior lamps (mercury vapor, low-pressure sodium, xenon) waste electricity and yield less.

Your plants deserve the spectrum they evolved for. Give them Metal Halide + HPS.