H.I.D. lighting stands for High Intensity Discharge, which is a special type of lighting that is much more intense than most other light sources available. HID lighting includes both High Pressure Sodium (HPS) and Metal Halide (MH) lighting. MH and HPS grow lights produce stronger, healthier seed starts, faster maturing plants, higher yields and increased flowering. HPS and Metal Halide lighting not only supplements sunlight but can replace it during the winter months. The light spectrum range produced by HPS or Metal Halide light bulbs enhances the natural light derived from the sun. In addition HPS and Metal Halide lighting is energy efficient and only requires about the same amount of energy as a standard kitchen appliance. The life of MH and HPS bulbs ranges from 6,000 to 20,000 hours depending on the wattage and bulb type.

MH lamps provide more of the blue/green spectrum, which is ideal for leafy crops, and/or plants that are in a vegetative (actively growing) stage. MH lamps provide a more natural appearance in color and are typically the choice for plants that have little to no natural light available. HPS lamps provide more yellow/orange/red spectrum, which is ideal for most plants that are actively fruiting and flowering. In addition, HPS lighting is the choice for growers looking to supplement natural sunlight. Ideally, the horticultural will use MH to grow their plants and HPS to fruit and flower their plants. HPS Grow Lights are available in 250, 400, 600 and 1000 Watts. Metal Halide grow lights are available in 250, 400 or 1000 Watts.

NO. HID lighting requires a special ballast or transformer to ignite the bulb or lamp. The internal components of the ballast are designed to send the correct voltage and current for the rated lamp. Mixing bulbs and ballasts will result in premature failure and will void the manufacturers’ warranty. Consider the size area you want your garden to be prior to making a lighting purchase. It is better to grow into a fixture than out of one. It is important to always match your ballast and lamp wattage and type. For example, do not use a 400W HPS light bulb with a 1000W HPS ballast. This may fire up the lamp but could cause the lamp to explode or will reduce its life. Also you cannot run a metal halide bulb on a HPS ballast or vice versa. The only exception is that a 430W HPS bulb will run on a 400W HPS ballast (see #4). Also, special bulbs called conversion light bulbs can be used to convert an HPS ballast to MH or vice versa (see #5).

Yes, a 430 Watt HPS light bulb will run on a standard 400W HPS ballast (Ansi S51). However, you will only receive 400 watts of light output.

A Light Bulb or Lamp that operates on the opposite ballast it was originally designed for. For example, a 940 watt conversion lamp is an HPS lamp that runs on a 1000 watt Metal Halide Ballast. There are also MH lamps that are designed to operate on HPS ballasts. These bulbs allow the grower to purchase the ballast of their choice and offer the flexibility of growing a variety of plant types by simply changing the lamp they need. Conversion Light Bulbs can be found here:

High Pressure Sodium Conversion Lamps (run on halide ballasts)
Metal Halide Conversion Lamps (run on HPS ballasts)

The "color" of light sources comes from a complicated relationship derived from a number of different measurements, including correlated color temperature (CCT) or Kelvin temperature (K), color rendering index (CRI), and spectral distribution (PAR Watts). However, color is most accurately described by a combination of Kelvin temperature and CRI.

• Color Rendering Index - CRI

  CRI is a numeric indication of a lamp's ability to render individual colors accurately. The CRI value comes from a comparison of the lamp's spectral distribution to the standard (e.g. a black body or the daytime sky) at the same color temperature. The higher the CRI the more natural and vibrant the colors will look. A bulb with a CRI of 85 or higher is excellent being that the sun has a CRI of 100. Eye Hortilux makes 90 -92 CRI bulbs that are used in aquarium, horticulture and other applications such as the 400W Eye Hortilux Blue 90CRI and 1000W Eye Hortilux Blue 92CRI. Standard Metal Halide bulbs have a CRI of about 70, so only 70% of colors will be rendered correctly. HPS bulbs have a CRI of 22.

• What is the Color Temperature or "K" - Kelvin Rating?

  The K rating is a generalized form of addressing the color output of a Light Bulb. Color Temperature is not how hot the lamp is. Color temperature is the relative whiteness of a piece of tungsten steel heated to that temperature in degrees Kelvin. HPS has a warm (red) color temperature of around 2700K as compared to MH at 4200K, which has a cool (blue) color temperature. The higher the kelvin temperature gets, the bluer. 10k lamps seem to be a nice crisp white, while higher kelvin can go from a blue/white to very blue and lower kelvin seem more like that of sunlight (6500k). Metal Halide bulbs go up to 20,000K (commonly used in aquariums) providing the bluest light.

• What is Spectral Energy Distribution & PAR Watts?

  The total visible spectrum is perceived by us humans as white light, but the "white light" is actually separated into a spectrum of colors from violet to blue, to green, yellow, orange and red made up of different wavelengths. Plants use the blue to red part of the spectrum as their energy source for photosynthesis. The different combinations and the relative intensity of various wavelengths of light determines the CRI of a light source.

  Only part of solar radiation is used by plants for photosynthesis. This active radiation Photo synthetically Active Radiation (PAR) contains the wavelengths between 400 and 700 nanometers and falls just within the visible spectrum (380 - 770nm). The light in this region is called PAR watts when measuring the total amount of energy emitted per second. PAR watts directly indicates how much light energy is available for plants to use in photosynthesis.

• What is the Lumen Measurement?

  Lumen is a measurement of light output. It refers to the amount of light emitted by one candle that falls on one square foot of surface located at a distance of one foot from the candle. Traditionally, lumens have been the benchmark of a lamps ability to grow plants; meaning the brighter the lamp the better the plant. However, studies have shown that a broader color spectrum lamp will perform much better than a lamp with high lumen output, especially when it comes to plant growth.

Metal Halide and HPS grow light systems are perfectly safe to run in your home. All of our grow light systems are manufactured by Sunlight Supply and are UL listed. The UL listing indicates the grow light has been properly tested for safety.

Manufacturers do not indicate that gloves are required when handling MH or HPS Bulbs. However, it is recommended that your hands be thoroughly washed prior to handling these bulbs. However you should handle MH HQI double-ended bulbs very carefully and should wear gloves.

The inner arc tube of a Metal Halide lamp contains mercury. Underwriters Laboratory has stated that for a Metal Halide fixture to maintain its UL Listing, that an additional tempered safety lens is required in the event that the arc-tube and outer glass fail. This will prevent the spread of Mercury.

This depends on the type of plants and whether you have natural sunlight available to your garden. As a general rule, when you are in a vegetative stage of plant growth and you have no natural sunlight, run your lights 14-18 hours a day. If you have natural sunlight, it will vary because the sunlight may or may not be direct. It will take a little experimenting to find the best length of time to run your lights. If you are actively fruiting and flowering, the rule is to run your lights 12 hours a day if you have no natural light

HID (MH/HPS) bulbs should be replaced after 12 to 18 months of use. Although MH and HPS lamps will continue to light beyond 18 months of use, they will have lost up to 30 percent or more of their lumen output while consuming the same amount of electricity. The average life of a MH lamp is 12,000 hours for a 1000 watts lamp and 20,000 hours for a 400 watt lamp. The rated life hours for most HPS light bulbs is 24,000 hours. Most manufacturers rate their lamps by “Average Life Hours” and usually claim 10,000 to 24,000 hours. These ratings are based on when the lamp/bulb will completely fail to come on. They do not factor in loss of intensity or loss of color. MH and HPS light bulbs lose intensity and color through normal use. This is OK if you are lighting a warehouse, but when it comes to plant growth, these losses can mean wasted electricity and poor plant performance. Serious horticulturists recommend that replacing HPS or MH Light Bulbs after 6000 hours of use. This equates to using your light 16 hours a day for one year.

• It may take MH or HPS bulbs 10-15 minutes to come to full brightness.
• During the first few hours of use, the light from the lamp might oscillate.
• The light will decrease in intensity during the life of the lamp.
• During the first hours, intensity of the light may fluctuate somewhat, which is normal. After 100 hours of “burn in” time, the bulb will continue to burn evenly for the remainder of it's life (with normal aging reduction).
  
  

A Remote ballast kit is a system where the Ballast or transformer is a separate unit from the reflector. An enclosed Ballast light kit is a light system where the reflector and ballast are integrated in the same metal housing of these grow lights.

• Ballast
• Reflector with Socket & Cord
• Light Bulb

A Remote ballast kit is a system where the Ballast or transformer is a separate unit from the reflector. These ballasts are extremely heavy and some models are made to be wall mounted while others can simply be placed on the floor. Most of the items we sell are lighting systems (kits) for growing plants, herbs, seeds, and for greenhouses applications. Many of the items we offer are sold as Kits with many different options and components. A complete remote ballast grow light system would consist of a ballast, reflector, socket & cord and light bulb. The ballast (transformer) is needed to ignite the bulb. The reflector or hood is what is used to direct the light and usually has a reflective insert to provide greater light intensity. Many of the reflectors now come with the socket & cord pre-wired into the hood. The example to the left is item# 400HPSYLD1: 400W Sun System 1 Ballast with Yieldmaster 2 reflector and 400W HPS Bulb. So the components that would automatically be included in this system would be:

• 400 Watt HPS Sun System 1 Ballast
• Yieldmaster 2 Reflector with 6in. Fittings
• Standard 400W HPS Light Bulb. You have the option to upgrade your bulb. For more information on bulb upgrades go here.

An enclosed Ballast light kit is a light system where the reflector and ballast are integrated in the same metal housing of these grow lights. A complete enclosed ballast grow light system would consist of a ballast/reflector reflector with and integrated socket & cord and light bulb. The example to the left is item# 900507 Sun System 2 - 400W HPS System. So the components that would automatically be included in this system would be:

• Sun System 2 - 400W HPS Fixture
• Standard 400W HPS Light Bulb

Sunlight Supply carries three lines of HID ballasts in their Good, Better, Best Lines include the Sun System 1, Sun System Harvest Pro and Sun System 10. There are a variety of differences between these ballasts. Below is a summary of the different features of these Ballasts. To view the comprehensive comparison page go here: Compare Sun System Ballasts

GOOD	BETTER	BEST
Sun System 10   Econo Gro Imported 120/240V ballast Power slider for switching voltage White powder coat Die cast aluminum housing 6ft. 120V Smart Volt power cord (included) Switch to 240V with optional 240V cord (sold separately) Accepts 15ft. power cord & socket (sold separately) Rubber feet Side louvers for cooling Standard carrying handle 5 Year Warranty	Harvest Pro/ Harvest Pro Elite Imported 120/240V ballast Power pointer for switching volts Two-part ballast enclosure (Elite model only) EZ Cap door for capacitor access Aluminum ballast enclosure White powder coated finish 6ft. 120V Smart Volt power cord (included) Switch to 240V with optional 240V cord (sold separately) Accepts 15ft. power cord & socket (sold separately) Louvered end & side plates Rubber feet and carrying handle 5 Year Warranty	Sun System 1 & 6 Ballasts U.S. brand 120/240V ballast Aluminum heat sync housing White powder coated finish Power pointer for switching volts Two-part ballast enclosure EZ Cap door for capacitor access 6ft. 120V Smart Volt power cord (included) Switch to 240V with optional 240V cord (sold separately) Accepts 15ft. power cord & socket (sold separately) Louvered end plates Rubber feet High temperature capacitor Heavy duty key-way handle 5 Year Warranty

Switchable light ballast grow lights allow using either a Metal Halide or a HPS lamp. To change from one type of lamp to the other, insert the appropriate lamp and set the switch. This enables growers to use the proper spectrums for vegetable growth (MH) and flowering (HPS) with a simple to use switch. The switchable ballast grow light kits that we carry include everything you needs including HPS Bulb, Metal Halide Bulb, Sun System 6, or Harvest Pro Switchable Ballast, Reflector with lamp cord & socket assembly and power cord. You can purchase a complete switchable ballast grow lights here.

Frequency output to the lamp and energy conversion from electricity to usable light are the biggest differences between HID (MH & HPS) ballasts and electronic ballasts. HID ballasts produce a frequency of 60 Hz. Electronic ballasts vary from manufacturer to manufacturer, but the frequency produced can be 400x that of an HID ballast. HID ballasts produce more heat than electronic ballasts, thus making electronic ballasts more energy efficient. You will not, however, save money on your electric bill by using electronic ballasts. HID lighting has been available for 60+ years, while electronic ballast (especially 400 watt and higher) is a relatively new technology. The Galaxy 400W Electronic Ballast is pictured left.

Are electronic ballasts more energy efficient?

Electronic ballasts are more efficient at converting electricity into usable light. Since your power bill is based on kilowatt-hours and not efficiency, a 1000 watt electronic ballast will cost you about the same as a 1000 watt HID ballast to operate.

An average lighting system will increase your electricity cost about $8 to $20 per month. The exact amount depends on the wattage of the system and the number of hours operated. To calculate your cost, multiply the bulb wattage X the number of hours of operation and divide by 1000. This figure is the number of kilowatt-hours of electricity used. (Example: a 400 watt lamp running for 18 hours will use 7.2 kilowatt-hours). Check your power bill for the cost of each kilowatt-hour. Then multiply the number of kilowatt-hours used by the cost of a kilowatt-hour (K/hr) to figure the cost to run your light for that many hours. Download the electricity cost guide for Sunlight Supply Fixtures.

Do I need special wiring in my house for my lighting system?

Lighting systems are available in a variety of voltages. The standard used by most gardeners is 120 volts / 60 Hz which plugs into a standard wall outlet. Other voltages may require special circuits and receptacles. Always contact a licensed electrician if the light you purchased has special voltage requirements and never exceed more than 75% of the rated ability of the fuse/breaker. (For example: use no more than 15 amps on a 20-amp circuit.)

What voltages are available for HPS & MH lights?

Most HPS & MH Lights Systems are available in 120 volt, 208 volt, 240 volt, 277 volt and 480 volt at 60 Hz. Sunlight Supply ballasts are multi-volt ballasts however they come standard wired for 120V. Most models can easily be run on 240V without any special wiring. You will just need to purchase the optional 240V power cord for the particular ballast your are ordering. However most ballasts can be special ordered to be wired for any of the voltages listed above.

MVP is Sunlight Supply's Multi-Volt Power cord feature for previous models of the Sun System 1 & 6 Ballasts that allowed switching from 120 to 240V by simply switching cords. However, in early 2009 all Sun System 1 & 6 Ballasts will be re-designed to use the Smart Volt Power detachable power cord (pictured left) to switch from 120 to 240V. The Smart Volt Power Cord is the same cord that most of the other Sun System Ballasts now use to easily switch from 120 to 240V including the Sun System 10, Harvest Pro and Galaxy™ ballasts. All Sun System ballasts that use the Smart Volt cord come standard with a 6ft. 120V Power Cord. Purchase the 240V cord separately to run the ballast on 240V. The Smart Volt Cord is also available in 20ft. for both 120V & 240V. However the 120V 20ft. cord is NOT RECOMOMMENDED to be used with any of the MH/HPS ballasts and could cause a safety issue. The 120V 20ft. cord should only be used with the Galaxy Electronic Ballasts.

Yes. If you need a longer bulb cord to extend the length between placement of your reflector and ballast a bulb cord extension is available item #903245. This extension cord plugs into the cord receptacle on a Sun System?ballast then into the plug on the bulb cord coming from the reflector. This allows increasing the distance between the ballast and reflector by 10ft. This bulb cord extension works with any Sun System Reflector that has a pre-wired 15ft. lamp cord & socket built into the reflector. This extension cord also works with the standard 15ft. Lamp Cord & socket #903055. A 10ft. (14 gauge) extension item #903247 is also available to work with our 25ft. lamp cords 903060.

Running your light system on 240 Volts generally will not provide any benefits. Since Electric companies base your electrical bill on Wattage, not Voltage or Current you will not receive energy savings. However, ballasts wired for 240 volt will draw less current and run a little cooler than 120 volt ballasts. Note that your outlets must be setup to use a 240V plug in order to use a 240V system which is not a standard plug and is normally not the standard outlet receptacle in most households. If you want to run your system on 240V you will need consult with a licensed electrician to determine what changes need to be made to run a 240V light system.

NO. All Sunlight Supply (Sun System) ballasts are only compatible with Sun System Reflectors. All Sun System ballasts have a proprietary female bulb cord receptacle that fits their patented male bulb cord. Most of Sunlight Supply Reflectors include the required socket assembly and lamp cord built into the reflector.

NO! If you purchase just a Sun System Ballast (not a kit) you must purchase a mogul 5kv socket or socket and lamp cord for your reflector and bulb.

• Adjust-A-Wing (with or without lamp cord)
• Agrotech
• Cool Sun 6in.
• Cool Sun XL 8in.
• Econowing
• Great White (NEW)
• LumenMax® 2
• Magnum XXXL 6"
• Magnum XXXL 8" (the Ocho)
• Light Pipe™ 6” & 8” (socket only, no lamp cord)
• Silver Sun (NEW)
• Sun Tube ™ 6” & 8”
• Super Sun (Classic)
• Super Sun® 2
• Yield Master™ 4in.
• Yieldmaster 6in.

• Sun Gro
• Lumen Max

• Cool Sun
• Cool Sun XL
• Sun Gro
• Great White (NEW)
• Magnum XXXL 6"
• Magnum XXXL 8" (the Ocho)
• Large Convertible (NEW)
• Agrotech Magnum (NEW)
  
  

The BT-56 Metal Halide bulb size was the standard size for many years. However, the reduced jacketed BT-37 sized Metal Halide Light bulbs will provide the same intensity and color as a BT-56 light bulb provides. The BT-37 Metal Halide bulbs are physically smaller and much easier to ship and handle and fit in more fixture types. Be sure to verify that your fixture will accept a BT56 sized bulb before purchasing, but when in doubt the BT-37 has become the standard size for most Metal Halide fixtures.

Sunlight Supply Manufactures a wide variety of Reflectors in various shapes and sizes. Sun System reflectors offer a variety of features such as advanced reflectivity with 95% German Aluminum inserts, adjustable wing style reflectors, Horizontal Reflectors with built in air cooled openings and a variety of other features. To compare all of Sunlight Supply's Reflectors visit this page.

• Sun Lift - holds up to 22lbs, allows height adjustment using tension mechanism (maximum extension is 4.5ft.)
• Light Hanger - holds up to 40lbs, allows height adjustment similarly to blinds
• Grow Yo-Yo - holds up to 22lbs. , allows height adjustment like a yo-yo
• Cable Hanger - can be used with New Wave and Tek Lights. Allows raising and lowering fixture.
• Jack Chain - Heavy duty Jack chain is a common way to hang heavy fixtures and ballasts to supports. Can be purchased at most hardware stores.
  
  

The higher the wattage the further away you want the light to be from your plants due to the amount of heat. HID lighting will be further away than a fluorescent fixture because of this. When mounting your lighting fixture take into account the type of plant and how tall the plant will grow. You want to keep the light as close as you can, but not so close to burn the plant. A simple rule is “if it is comfortable for the back of your hand, it will be a safe distance for your plants”. Doing a little research on the type of plant and where it comes from will help in determining how much (or little) light your plants like. With fast growing plants, you may need to check the hanging height on a regular basis as plants that get too close to the lamp will be severely burned.

The size of the garden area will determine the wattage you need. If we assume that the plants will get no sunlight, a 1000 watt light will cover about 7 x 7 feet of growing area. A 600 watt will cover 6 x 6 feet, a 400 watt will cover 4 x 4 feet, and a 250 watt will cover 3 x 3 feet. These sized areas would be considered the “Primary Growing” areas. These lights will light-up larger areas, but plants placed outside of the Primary Growing area, will stretch and bend toward the light; a phenomenon called phototropism. Keep these areas of coverage in mind when using multiple fixtures. The best results occur when the areas of coverage overlap.

Warm water and mild dish soap are the best to clean and maintain the highly reflective finish. Avoid bleach, ammonia and other harsh or abrasive cleaners.

The way the reflectors are air cooled is by attaching a fan and ducting to the reflector and venting the heat from the reflector to the outside. This requires the purchase of a an inline fan or blower and ducting in addition to an HPS or MH Light Kit with a Reflector that can be Air Cooled. There are a variety of fans to choose from depending on the wattage of your light system, the size of the room, whether there is any existing ventilation and how you want to setup your system. The photo (bottom right) shows one example of how a 1000W HPS Light Kit with a Sun System 2 Reflector can be air cooled with an Ecoplus inline fan. The image bottom left shows air cooling using both ducts.

Download a PDF diagram of air-cooling two reflectors with one fan and ducting.