The question of LED vs HPS and which is "better" has been around since the LED grow light hit the market. While LED grow lights have certainly come a tremendous way since, can they compete, watt for watt, with the HPS grow light? And where do other types of HID grow lights come into play?
If you look to any online grow forum, you will constantly find growers debating whether HPS or LED lighting is best. It is interesting that if you were to check 4 or 5 years ago, HPS would be the clear winner of the debate. However, LED grow light technology has grown leaps and bounds over the last few years, and the debate these days is much less clear. LED grow lights are now boasted by many as the best way, dollar for dollar, to a successful grow with the best yields.
The pricing of LED grow lights has also dropped substantially over the last few years, which makes the argument for LED grow lights stronger. Those who have been using HPS lights for years may resist the change to LED grow lights, particularly because of a higher upfront cost. However, LED grow lights are typically cheaper to operate in the long run thanks to reduced power consumption and elimination of regular maintenance. With HPS grow bulbs, the intensity drops off significantly over time so you will have to replace your HPS bulb regularly to ensure you are getting the most out of your grow light. LED grow lights don’t lose intensity like HPS bulbs and are typically just as bright until the very end of their life cycle with a general lifespan of 50,000-100,000 hours.
High Pressure Sodium lights have often been seen as the best grow light available for amateurs and professionals alike, and the key to their popularity is their incredible raw light output. HPS grow lights produce a massive amount of light, which is especially good for flowering; however, they also produce a great deal of heat in doing so and much of the actual light produced is of lower value for growth. Those who use HPS lights most often use Metal Halide for vegetative growth as well since its light spectrum is better suited for vegging. This means that many growers with HID light setups have separate veg and flowering lights or at least multiple bulbs, which adds to the expenses of maintaining an HID setup.
Pros of HPS
- HPS lights are more standardized among manufacturers, making it a bit easier to comparison shop.
- HPS light setups have a cheaper initial start-up cost, but the price gap between comparable HPS and LED grow has become much smaller as LED grow light setups have become more and more affordable each year.
- HPS bulbs provide an immense amount of raw light intensity so they can produce great yields, particularly when working with very large plants.
Cons of HPS
- HPS lights use much more electricity to generate light than comparable LED grow light setups and are thus much less efficient.
- HPS lights also generate a lot of heat, which often requires additional ventilation equipment to maintain a proper grow room temperature. If not dealt with accordingly, the added heat can make growing very difficult. This is especially challenging if your grow area is already prone to heat issues (growing in a hot attic, for example).
- HPS grow bulbs diminish in intensity significantly over time and must be replaced regularly every 12-18 months resulting in additional operation costs.
LED Grow Lights
LED grow lights are a truly remarkable feat of technology and are by far the most efficient lighting type available. Used in some of today’s most cutting-edge commercial grow operations as well as many hobbyist gardens, LED grow lights combine precise spectral outputs, advanced optics, and thermal management engineering to convert nearly 100% of consumed power into growth-targeted light energy. This is how LED grow lights are able to produce great yields while consuming far less energy than their HPS counterparts. LED grow light fixtures also require very little maintenance aside from occasional cleaning. Typically, growers use just one LED grow light system from start to finish as most LED’s have spectrums optimized for the full growth cycle. There are also LED grow lights available that can be adjusted for the different phases of growth.
Pros of LED Grow Lights
- Today’s best LED grow lights can rival the production of HPS lights that use nearly twice the wattage, which adds up to great savings on the power bill.
- LED grow lights run much cooler than HPS resulting in an obvious set of benefits for the indoor grower.
- LED grow light units typically come as all-in-one fixtures, which are easier to work with in tight spaces. They can also be placed closer to plants in confined areas with very little risk of heat damage.
Cons of LED Grow Lights
- LED Grow lights do have a higher upfront cost but have been shown to save in the long run thanks to a lower cost of operation.
- LED Grow Lights are not as standardized across manufacturers quite yet, making comparison-shopping more difficult. Still, the LED grow light industry has come a long way and design practices are becoming more consistent.
- LED Grow lights produce very little heat, which for many is an advantage. However, those growing with LED’s in colder indoor areas may need to supplement the extra heat an HID light such as an HPS or MH would produce.
Both LED grow lights and HPS grow lights are equally capable of producing great yields, and both have advantages over the other. If initial cost is not an issue, the answer to which one is better really comes down to other main factors contributing to your grow such as the growing method you plan to practice as well as the ambient conditions and size of the grow area.