CMH Grow Lights vs HPS Grow Lights
HPS Grow Lights
HPS stands for High Pressure Sodium, this is a type of HID bulb that uses sodium and is considered the gold standard of grow lights. These bulbs generally come in 150w, 250w, 400w, 600w and 1000w versions and must be paired with a ballast that matches the wattage. HPS lights provide a full spectrum of light, but have an emphasis on the red end of this spectrum. They can be used for the entire life cycle of a cannabis plant, but many growers argue that the extra red light makes HPS lights optimal for the flowering phase.HPS lights are considered to be the ideal lights for growing cannabis for several reasons. They are relatively affordable and easy to use for the everyday grower, and perform very well. Despite several drawbacks, it is hard to beat the performance of HPS lights. Whenever new grow lights for indoor marijuana are developed, they are usually judged on how well they compare to HPS lights with a similar wattage.Double ended HPS bulb. HID bulbs come in regular and double-ended versions, make sure all your hardware matches your bulb!The downside to using HPS grow lights is their efficiency, the main problem is usually the heat generated by both the ballast and the light. With temperatures exceeding 400°C, this system does not use energy very efficiently. The penetration of these lights also diminishes very rapidly and can drop by almost 90% at distance of only one metre. These inefficiencies have caused the European Union to ban the production of High Pressure Sodium grow lights and stimulate the transition to more environment-friendly alternatives like L.E.D. lights.It is important to note that HID bulbs classically only connect at one side, but more modern grow lights use double-ended bulbs. These double-ended bulbs connect at both sides and are up to 30% more efficient than regular bulbs. Double-ended bulbs are simply better than single-ended bulbs, but this is also reflected in the price.In short, HPS lights are definitely very good for growing cannabis. However, the amount of power consumed can become expensive and unfortunately much of this energy is wasted as heat and sound.
CMH Grow Lights
Actually, Ceramic Metal Halide (or CMH) grow lights are not new; they were first developed in the late 60s, and it's not until recently that they are acknowledged and used commonly as grow lights.
Ceramic Metal Halide (CMH) or Light Emitting Ceramic (LEC) are two different terms, but both refer to the same technology. So basically, we can use these two interchangeably. In this article, I'll mostly use CMH.
A CMH grow light is like a Metal Halide (MH) bulb, but while a MH bulb uses a standard quartz arc tube, CMH is built with a ceramic arc tube. This is similar to the material used for HPS grow lights. So that's can be said that CMH is a mix between MH and HPS.
Since it uses ceramic arc material, CMH is less degradative than both MH and HPS with up to 20,000 hours of lifespan. CMHs can operate at a higher pressure and emit stronger light output than HIDs as well.
CMH Grow Lights vs HPS Grow Lights
Growing plants indoors poses all kinds of problems, but thankfully, modern technology has the solutions that readers are looking for. Arguably the best of these available on today's markets is the ceramic metal halide, or CMH, grow light. Whether readers are looking into indoor growing for the first time or they're just looking to upgrade from less efficient and less effective lights, they can read on to find out about a few of the advantages of investing in this impressive, thoroughly modern technology.
Longer Lasting
CMH lights feature ceramic arc tubes, which are known to be far more resistant than traditional lights to premature breakdown. CHM grow lights can last for more than 24,000 hours and maintain over 80% of their intensity for up to 20,000 hours. Compare this with the 10,000-hour life expectancy for high-pressure sodium (HPS) and traditional metal halide (MP) bulbs and it's easy to see why CMH lights are well worth the investment.
More Efficient
In addition to lasting as long as three years without needing to be changed, CMH bulbs are also able to convert electricity into usable light better than most other bulbs. CMH lights are up to 20 percent more efficient than traditional metal halide bulbs and feature a higher yield per watt than this antiquated alternative.
This increased efficiency over HPS and MH lights contributes to monetary savings over time, helping to offset the initial investment cost of making the switch. Not only will readers appreciate lower monthly utility bills, but they'll also be able to rest a little bit easier knowing that they've also purchased lights that use less of the planet's valuable natural resources.
Balanced Spectrum
With CMH lights, indoor growers can expect a balanced light spectrum that offers everything their plants need to facilitate optimal rates of photosynthesis. HPS and MH lights tend to waste electricity by converting it into light that is not optimized for plant photosynthesis, which requires a fairly narrow range of light. Their comparatively low photosynthetically active radiation (PAR) efficiency means that they have to work much harder to produce enough light to facilitate the conversion of light into nutrients, helping to explain their lower power efficiency and shorter lifespans.
Neither MH nor HPS grow lights offer a full-spectrum of PAR. MH bulbs have a tendency to be heavy on blue light, while HPS tend to be heavier on red light. The spectrum of usable light ranges from 400 to 700 nanometers, though, which is why it can be beneficial for growers to choose bulbs that offer a broader, more balanced spectrum. Those who want the added boost on the red spectrum that flowering crops need to grow at optimum efficiency should note that CMH lights can also be combined with HPS lights for maximum benefit.
Improved Color Rendering Index
The color rendering index, or CRI, is used to describe how a light source's color changes how objects appear to the human eye. It can cause subtle variations in color that make it difficult to tell how plants are actually faring in an indoor environment. Thankfully, the CRI for CMH grow lights is usually rated between 80 and 96, meaning that they are great at allowing the true colors of plants to shine through without the unnatural-looking color variation caused by MH and HPS lights.
Color Stability
In addition to offering a higher CRI, CMH grow lights provide consistent color rendering. Many grow lights tend to experience decreased CRI over time, decreasing their effectiveness in subtle ways and often leaving growers wondering why their plants aren't performing at peak levels. CMH lights, on the other hand, provide consistent light quality and maintain their wide light spectrum throughout the duration of their use.
UV Radiation
UV radiation may not be visible to the human eye, as it falls outside the range of light that people are able to perceive, but it is essential for plant growth. It's important to note that there are several types of UV light, known as UV-A, UV-B, and UV-C. UV-C is considered harmful to the human eye, which is why CMH grow lights block it out using a high-quality glass filter that does not effect UV-A or UV-B light transmission.
Thanks primarily to their balanced light spectrum, CMH grow lights provide more UV-A and UV-B light than many of their alternatives. This is essential for producing a healthy crop, as most plants require a good deal of UV light during their vegetative stages to support the development of strong, healthy branches.
Low Heat Production
It's important to purchase grow lights that operate at reasonably low temperatures, as excessively high temperatures can wind up damaging crops and negatively impacting their ability to produce optimum yields. CMH bulbs operate at lower temperatures than many of their alternatives. This allows them to produce sufficient light without overheating even smaller grow rooms and lets growers place them closer to their plants, helping to reduce the chances of burning the leaves.
No Electromagnetic Interference
Some grow lights and electronic ballasts can interfere with electronics like cell phones and television signals. This can be a major inconvenience for in-home growers. CMH grow lights don't produce electromagnetic interference, though, which means that they won't affect nearby electronics.
Falling Cost
The primary down-side of purchasing CMH lights has historically been their cost. Admittedly, they are more expensive than many cheaper grow lights. Continued advances in associated technologies and increases in consumer interest have recently been leading to falling prices, though, as CMH bulbs are produced in larger quantities by a wider variety of manufacturers.