Although LED Grow Lights are popular, many hydroponic growers still prefer gas-charged HPS or MH grow light systems. This is especially true for bigger commercial setups.

The intensity, broad spectrum, and light consistencies make HPS or MH lighting suitable throughout the entire plant cycle. The grow light system can be used for vegetative growth, and blooming.

What is the difference between HPS and MH lights?

The main difference between these two types of grow lights is the spectrum they produce. MH lights are blue and beneficial for plants in their early stages. On the other hand, HPS lights are red and more suitable for plants during the flowering stage.

The differences in the spectrum are due to the type of gas in each tube. Growers should have both types of HID lights to grow a healthy plant. Below is a more detailed breakdown of the two types of spectrums:

HPS Spectrum

The spectrum range for High-Pressure Sodium (HPS) lights typically falls within the yellow to red wavelengths of light. HPS lights emit light primarily in the range of 550 to 750 nanometers (nm). This range includes strong yellow and deep red wavelengths, which are particularly beneficial for promoting flowering and fruiting in plants.

HPS lights are popular for indoor gardening and greenhouses because they efficiently produce light in a specific range. This specific range of light is beneficial for improving plant growth. HPS lights are also often used in parking lots due to their powerful light source.

Most HPS bulbs fall within the 2,000 - 2,100 kelvin range for color temperature.

Metal Halide Spectrum

The spectrum range for Metal Halide lights encompasses a broader range of wavelengths compared to High-Pressure Sodium (HPS) lights.

MH lights emit light across the full spectrum, including blue, green, and red wavelengths. The spectrum range typically spans from around 400 to 700 nanometers (nm). The blue wavelengths (around 400-500 nm) promote vegetative growth and are ideal for the early stages of plant development. The green wavelengths (around 500-600 nm) contribute to overall plant health and canopy penetration.

The red wavelengths (around 600-700 nm) support the flowering and fruiting stages. The varied spectrum of Metal Halide lamps makes them versatile for both vegetative and flowering growth phases in indoor gardening.

Most MH bulbs fall within the 4,000 - 10,000 kelvin range for color temperature.

Benefits Of Using Metal Halide & HPS Grow Lights In Your Grow Room Or Grow Tent?

There are several reasons why High-Pressure Sodium (HPS) and Metal Halide (MH) grow lights are popular choices for indoor gardening:

• Established technology: HPS and MH lights have been widely used in the horticulture industry for many years. They have a proven track record and are trusted by professional growers for their reliability and performance.
• Versatility: HPS and MH lights cover a wide spectrum of light, making them suitable for both vegetative and flowering stages of plant growth. They provide the necessary light spectrum to support various phases of plant development.
• Light penetration: Both HPS and MH lights have excellent light penetration capabilities, allowing the light to reach deep into the plant canopy. This ensures that the lower leaves receive adequate light, contributing to balanced growth and healthier plants.
• Plant growth and yield: HPS lights are particularly effective in promoting robust flowering and fruiting, while MH lights stimulate vegetative growth. The specific light spectrums produced by these lights can enhance plant health, yield, and overall productivity.

Overall, HPS and MH grow lights offer a combination of efficiency, versatility, and proven performance, making them reliable options for indoor gardeners seeking to optimize plant growth and yield.

Should you go with an SE or DE grow light system?

Double-ended (DE) grow lights are powered by wires on either end of the bulb, resulting in more intense light. Single-ended (SE) grow lights are screwed into one end like a typical light bulb. Generally, the commercial grower will find the DE grow light provides more flexibility and a brighter, more efficient light. Beginners with a small indoor garden will get by perfectly with an SE grow light.

Final Thoughts On HPS & MH Grow Lights

Because of the versatility, cost, and reliability, HPS or MH grow lighting will not fall out of favor with the indoor grower any time soon. If you want to learn more about grow lights, visit our learning center blog about the best HPS grow lights or give one of our experienced growers a call at 888-815-9763!