What are your thoughts on HPS, CMH and LED?

Young-Canopy-Wide-Shot.jpg

Question by @Chrisbishyo


This is our blunt yet humble opinion on lights. It comes down to your grow space and budget. The goal of every light company is to replicate the sun as close as possible, without burning your plants.

HPS (High-Pressure Sodium) is king when it comes to flower rooms. HPS outputs more red spectrum than CMH lights. CMH (Ceramic Metal Halide) outputs the blue spectrum desired for mothers and vegplants. Another benefit of CMH is that it emits a UV (ultra violet) wavelength that stimulates plant growth and development.

LED (Light Emitting Diodes) are the wave of the future. Generally speaking LED provides a broader spectrum, is more efficient, lower heat output, longer life and the technology continues to improve. LED allows growers to dial in spectrums specific to the plant strain and lifecycle. Some LED companies are even offering infrared and UV lights to their board for further plant stimulation.

Heat output is an important consideration. HPS emits the most heat, followed by CMH then LED. The emitted heat can be utilized to warm your grow space in the winter, however you’ll need to cool down the rooms in hotter seasons or climates depending on where you’re located. So figure out what’s more economical, your heat bill or your AC (air conditioning).

Now for the actual cost of the lights. LED is expensive, especially the ones with UV spectrum. But if you plan on keeping your lights for many years, the upfront cost of the LED is worth it. Plus, LEDs will last longer than CMH and HPS bulbs (both have an average 18-month lifespan and lose about 20% efficiency after the first six months)

At Bloom Cultivation, our upcoming expansion will be fitted with CMH in our dedicated mother rooms, LED in veg, and HPS in our flower rooms. Our intent is to start the mothers off with a strong blue, transition into a broader full spectrum under the LED and then roll into a stronger orange/red for the flowering. Since our building is purpose-built, we can take advantage of the light options and optimize our plant growth at every stage.

Darryl Sinclair