LED FAQ (scroll down for HPS and MH FAQ)
What is LED?
What are nanometers?
Why don't you use Lumens to determine the power of your LED lights?
How can you replace the HPS and MH lights with LED’s at ¼ the power and expect the same results?
Do you need a reflector for LED lights?
How high do I hang LED Lights?
Do you need a fan to cool the LED lamp?
Are there different watering requirements using the LED lights?
How long should the lights be on each day?
Can I safely look directly into LED lights?
I have heard that LED lights do not perform well. Are LED lights as good as HID lights?

HID Lights and Electronic Ballast FAQ
What is HID?
Do I need different ballasts for 110V and 220V?
How can these ballasts consume less energy and still produce the same results?
How can digital ballasts help my bulb last longer?
Why do you recommend digital ballasts when you sell LED lights?
What is soft starting?

Air Cooled Reflector FAQ

What is the benefit of an air cooled reflector?
How do I choose an air-cooled reflector?

What is LED?

A light-emitting diode is an electronic light source. When the diode is forward biased (switched on), electrons are able to recombine with holes and energy is released in the form of light. This effect is called electroluminescence and the color of the light is determined by the energy gap of the semiconductor. The LED is usually small in area (less than 1 mm2) with integrated optical components to shape its radiation pattern and assist in reflection.

What are nanometers?

A common unit used to describe the manufacturing technology used in the semiconductor industry. It is the most common unit to describe the wavelength of light, with visible light falling in the region of 400–700 nm.

Why don't you use Lumens to determine the power of your LED lights?

Lumens reflect a measurement for visible light. For plant growing, this is not in any way a useful measurement. Originally, High Pressure Sodium and Metal Halide Lights were made for high output municipal lighting in the visible spectrum – to see in a park or on the road. Lumens are a measurement of the light energy a light source emits. This measurement is based around the wavelengths of visible light and not the PAR (Photosynthetic Active Radiation) wavelengths.

How can you replace the HPS and MH lights with LED’s at ¼ the power and expect the same results?

First, Positronics LED lights maximize light in the spectrum used for growing only and do not waste wattage on light in the unwanted spectrum (especially UV, green, and yellow light). Second, the new high-powered LEDs are very high output and produce more photosynthetic reaction per watt used than any other technology. Third, HPS and Metal Halide lights produce light in a radial pattern, requiring some sort of reflector to deal with directing the light in the desired direction and lose light bouncing between the reflector and bulb. This wastes energy. And finally, Positronics LEDs waste little energy in the form of heat as HPS and MH lights do. Metal Halide and HPS lights use over 50% of the electricity to produce heat and the rest left over to make the light. Positronics LEDs are more efficient in utilizing electrical power and convert very little energy to unwanted heat.

Do you need a reflector for LED lights?

All LEDs are directional. Based on the way light shoots off the flat diode, LED lights are excellent in controlling the exact placement of the light in the desired direction towards your plants. Traditional lights produce light in a radial pattern, 360 degrees, requiring a reflector to direct the light. Reflectors are never 100% perfect and will always result in some light being lost to refraction and absorption.

How high do I hang LED Lights?

We recommend you hang the lights between 10-30 inches from the plant tops, depending on the wattage and variety of plants you grow. We include a height reference in the packaging when you buy our lights.

Do you need a fan to cool the LED lamp?

Our higher-output lights (over 90W) come equipped with fans inside to cool the diode panel. Our lower wattage lights do not produce enough heat to need separate fans for cooling. However, note that air movement in a space is important to aid in respiration (essentially CO2 in and O2 out) so introducing fresh air into the room periodically is always necessary regardless of temperature.

Are there different watering requirements using the LED lights?

Yes. Plants grown under the LED lights use less water than those grown under conventional grow lights because of the evaporation caused by excessive heat. Therefore you water much less frequently. The time between watering will vary with plant species. Be careful no to overwater!  Over watering will slow root development, stunt plant growth, and cause nutrient uptake issues. We recommend an airy soil with lots of perlite or peat moss to avoid this from happening.

How long should the lights be on each day?

We do not recommend that you keep the lights on for 24 hours nor is it necessary for any plant to grow. While this should not harm the light, most plants benefit from daily rest, even as little as 4-6 hours. Check the library, internet, or with your local nursery to find out the preferred light/dark period for the plants that you are growing.

Can I safely look directly into LED lights?

The light emitting diodes (LEDs) used in our led grow light are very high intensity. Never look directly into the light at a close distance, or for long periods of time.

I have heard that LED lights do not perform well. Are LED lights as good as HID lights?

The folks at Positronics have been growing indoors for over 20 years. We are practical and believe in the right tool for the job. LED lights have shown time and time again in clinical studies to grow a vigorous and healthy plant. They emit no detectable light for your safety. They also have their place in the indoor and greenhouse industry. As with any other industry, there are charlatans and fakirs in the grow light business. Not all lights perform the same. Positronics LED grow lights are the top rated grow lights in the US, made from quality materials and the #1 American-made Cree LED chips. We recommend Positronics LED Grow Lights for vegetative growth, rooting cuttings, nursing stressed or damaged plants, supplemental lighting in greenhouses, and starting seeds. For blooming plants, we recommend LED grow lights to be used differently than traditional HID lights. LED lights are brightest within 36 inches of the panel surface. In situations where you are challenged with vertical space, Positronics LED Grow Lights are the perfect solution. We also recommend that you grow a shorter, more stout plant to avoid raising the light too high. When you raise the light too high, the lower branches of your plant do not get enough light and will not product a high yield. In short, people need to know how to use LED lights effectively, but the results are undeniable, they are excellent lights for growing plants!

Electronic Ballast FAQ

What is HID?

HID means High Intensity Discharge. This refers to the intensity of light generated by the power of the ballast and the gas contained within the bulb. Regarding growing plants, these include basically Metal Halide and High Pressure Sodium. Metal Halide Lights, being higher in the blue spectrum, are good for both vegetative growth and flowering, but better for vegetative growth as they promote short internode spacing and lush, wide leaf blades. Blooming plants flourish under High Pressure Sodium as it is higher in the red and orange spectrum of light.

Do I need different ballasts for 110V and 220V?

No, our ballasts are digital electronic ballasts which handle electrical input in a different way from the old magnetic ballasts. They are wired to recognize input current and adjust automatically. No switches, just plug and play!

How can these ballasts consume less energy and still produce the same results?

Electronic ballasts utilize digital technology to convert power to usable energy for the light bulb, which keeps the ballast cooler at all times. Magnetic ballasts, because they regulate power by a massive coil, generate more heat, effectively using more energy to make the conversion to usable energy. The heat generated in essentially wasted energy that is consumed in addition to that needed to power the bulb.

How can digital ballasts help my bulb last longer?

The electronic regulation of energy allows a smooth stream of electricity to the bulb, limiting fluctuations in power to the bulb. These fluctuations can cause the bulb element to receive levels of current not in line with the bulb’s intended range. Keeping the current regulated will reduce stress and increase longevity.

Why do you recommend digital ballasts when you sell LED lights?

At Positronics, we are practical. We believe in the right tool for the job. We have been using HID lights for 20 years with excellent results and they have improved the technology to meet the demands of growers like you. We also believe that there are applications where each different technology outperforms the other. For larger, more conventional grow operations requiring 600W, 1000W lights, or especially multiple lights, larger greenhouse supplemental light, and blooming plants where vertical space is not an issue, we recommend our low-energy consumption digital HID lights. They are more energy efficient than other digital ballasts, provide intense light and are safe and easy to use. LED lights have their place as well and we believe that they are due respect in those applications. If you ever have questions about which is right for you, we are only a phone call away – and we LOVE to talk about this stuff!

What is soft starting?

Digital ballasts start by sending a low amount of power to the bulb and steadily increase the power over the next few minutes until the bulb has reached full brightness, which minimizes the damage to the bulb and increases its PAR life. After one year of use the plant usable light coming from bulbs that are run on digital ballasts has decreased only by 20-25% where as the same bulb being used in the coil type ballast would have lost 50-60% of its plant usable light over the same period of time.

Air Cooled Reflector FAQ

What is the benefit of an air cooled reflector?

Air cooled reflectors are a major breakthrough in indoor gardening. In the past, it was recommended that you keep the lights 18-24 inches from the tops of your plants. This creates a problem for many growers. As your plants grow taller, the bottom branches are farther away from the light. All light sources except the sun have an “effective depth” which means that a certain distance from the bulb does not produce intense enough light to create flowers and fruits of value to the indoor gardener. Positronics Air cooled reflectors allow you to keep the bulb surface much cooled, in effect allowing you to keep plants closer to the light – within 6 inches!! This allows the bottom branches to produce a fruitful yield and allows the tops to really bloom to full efficiency. In addition, air-cooled reflectors also help maintain an overall lower room temperature, effectively allowing greater control over the climate in your grow room. Note, a Positronics Centrifugal Fan is functionally necessary to be able to utilize the benefits of an air-cooled reflector. Always use the correct fan for the size opening in you air cooled reflector and ALWAYS bring air in from outside. An air-cooled reflector should NEVER be used for ventilation of the entire room.

How do I choose an air-cooled reflector?

Positronics has a complete line of reflectors with a cooling function. Your choice has to be a combination of affordability and function. There are two main functions of an air-cooled reflector. First, they disperse light within the area to maximize the power consumption of your power supply. Second, they keep your bulb and room cooler. If you read the descriptions of our reflectors, we will rate the effectiveness of both functions as to their ability to perform both actions. You can ultimately chose the reflector that fits your budget and function needs. If you ever have questions about which is right for you, we are only a phone call away – and we LOVE to talk about this stuff!