LED vs HPS Lights for Growing Plants Indoors.
HPS and LED lights are the backbones of indoor growing with both lights used to mimic the sun so as to enable plant growth indoors. The battle for supremacy between HPS and LED lights have been asked times without number since the advent of LED into the market. A lot of growers in various online forums have constantly debated which is best amongst the two. HPS lights are warm, very bright and are very suitable for the indoor growths of plants, while LED lights are the new kid on the block running equally as bright, less warm and provide remarkable energy savings.
Though LED grows lights have come a long way, a few years back this argument wouldn’t stand because HPS would have come out on top easily. Let’s take a look at the pros and cons of both lights when used for indoor growing, costs associated with it and their lifespan.
Pros of HPS Lights
HPS (High-Pressure Sodium) lights are the ideal grow light if you are an amateur or professional indoor plant farmer, and the reason for their popularity is its incredible raw light output.
High-pressure sodium lamps have long been a staple of indoor growing. They are favored amongst growers because of their ability to produce a variety of light across the lighting spectrum and because they can be used in all stages of plant growth, from the vegetative to the flowering phase. HPS lamps emit a lot of light in the red spectrum, which improves the flowering stage, and more than average light in the blue spectrum, which is beneficial during the growth cycle of the plants.
HPS grow light fixtures have a few advantages that work for them. To start with, they’re relatively cheap. For example, you can get a 250 or 400-watt reflector complete with ballast at an inexpensive price; what you only need is to supply the HPS lamp. Replacement kits are quite inexpensive too.
HPS lamps come with a hood, ballast, and lamp which you can replace separately. If you pay careful attention to the ballast and bulb, you can considerably improve the lifespan of an HPS lamp saving you additional cost in the long run.
They generate a lot of heat, of which heat is highly unfavorable to plant growth. So it’s essential to have air circulating well throughout your grow space. In addition to that, the cost of adding a ventilation system will increase the cost of your indoor growing experiment.
Another shortcoming of HPS bulbs is the lifespan. You may say a bulb expected to last about 24,000 hours isn’t too bad, you’ll end up changing those bulbs sooner than you think. For example, during the flowering stage, your plants will need a minimum of 12 hours of light, while it needs about 18 hours of light during the vegetative stage. So if we calculate correctly, a 250-watt HPS bulb rated 24,000 life hours will be expected to last about 1,333 days, that’s roughly about 3 ½ years. The figures aren’t too bad but when compared to LEDs, it becomes a con.
The second an HPS bulb is powered on, the quality of light gradually declines. For best growing results, you have to replace these bulbs every 9 to 12 months, which leads to additional costs to your farming equipment.
Pros of LED Lights
LED grow lights emit very little to no heat, unlike HPS lights. This, therefore, eliminates the need for a circulation system as the heat emitted doesn’t pose a threat to your plants.
LED grow lights typically use three LED sources of different colors, they cover both ranges for growth and flowering extremely well by emitting adequate light across the three different spectrums.
LED grow lights are rated four times than HPS bulbs. A 165-watt bulb LED grow light, for example, is rated for 80,000 life hours, equating to roughly 12 years. The calculation is based on using the lights for about 18 hours every day during the vegetative state.
LED grow lamps are usually a complete kit with few, replaceable parts. LED fixtures don’t have to be replaced nearly as often as the HPS bulbs, which also reduces your recurrent costs in the long run.
What about energy efficiency? The 165-watt grow light used as an example above is equal to a 200-watt HPS bulb, but only consumes 165 watts, in so doing saving you 35 watts and reducing your energy bill.
For the adequate growth of plants, there needs to be a mixture of cool and warm light. Tall and lanky plants grow well under the cool light, while warm lights produce shorter, fuller plants. With LED bulbs, both tones are obtainable in a single bulb, striking that exact equilibrium your plants need to grow perfectly.
The major disadvantage of LED fixtures is its price. Just like household bulbs, LED fixtures are remarkably costlier than standard light fixtures, about double the price to be exact. The cost upfront is quite significant and is a major disadvantage for indoor plant growers.
Using LED grow lights in cold regions is a disadvantage since they produce little or no heat, you may need to get heating equipments to provide an adequate temperature for plant growth which also increases cost.
Deciding which light is best for your indoor growing is totally up to you. To be honest, either HPS or LED will work just fine for your indoor growing. The choice whether you want to spend the extra money up front and not have to burden yourself with changing your fixtures for a decade or spend less at your initial cost and over time keep changing the fixtures. Most growers go for what they know and are familiar with, so HPS usually gets the go-ahead. But as LED prices drop and technology evolves, we should see more and more diodes being used in indoor grows.