Can I use natural sunlight to grow plants indoors?
Yes, some gardeners take advantage of natural sunlight either in the greenhouse, beside a window or even by using skylights and solar tubes to light their gardens. Just be careful not to interrupt your plants dark cycle if it requires uninterrupted darkness.

What is High Pressure Sodium lighting and what is it good for?
A High Pressure Sodium light is a gas-discharge lamp that uses sodium in an excited state to produce light. HPS lamps have been the standard in indoor gardening for many years due to their ability to produce high intensity light in the red and orange color spectrums. This light is ideal to trigger a flowering response in flowing plants. This type of light has been shown to create large yields of high quality fruit and flowers. The downside to these lamps is the inefficiency of the lamps which can be noticed by the amount of heat that they produce. They also produce most of their light directly beneath the lamp making them more ideal for fewer large plants compared to many smaller plants as dispersing the light in an even pattern can be very difficult. With today’s technology growers are starting to employ the use of more efficient Induction Lamps and well as LED grow lights to more evenly disperse their light and lower the need for large ventilation or air cooling systems.

What is the difference between Digital and Magnetic HID ballasts?
Magnetic ballasts are the older type of HID ballast. They are constructed with a core and copper coil. They typically run very hot and emit a hum or buzzing sound during operation. They are typically only able to fire one type of lamp, either MH or HPS. There are however conversion lamps for magnetic ballasts that allow the opposite lamp type to be used (HPS in MH ballast or vise versa). Newer magnetic ballasts are switchable between lamp types. Digital ballasts run much cooler than magnetic ballasts. They also are more efficient; meaning more of the power consumed is used to produce light rather than heat. They have several other benefits such as soft starting lamps, a convenient dimming feature and most importantly the ability to run either MH or HPS lamps on both 120v and 240v power supplies. They are also much lighter than their magnetic counterpart so shipping can be much cheaper.

What types of lighting are suitable for indoor gardening?
There are several types of lighting all suitable for use in an indoor garden. Each has its advantages and disadvantages. The main types of garden lighting are:

  • Fluorescent
  • Induction
  • L.E.D
  • Metal Halide
  • High Pressure Sodium
  • Sulphur Plasma

What is a conversion lamp?
Conversion lamps are less popular these days due to switchable ballasts and digital ballasts which auto detect and fire both types of HID lamps. However, in a situation where you are running a magnetic HID ballast and want to run the opposite lamp than when your ballast is rated for, you are able to use a conversion lamp to accomplish this. Conversion lamps are typically more expensive than a standard MH or HPS lamp.

What is Fluorescent lighting and what is it good for?
A fluorescent lamp, fluorescent tube or compact fluorescent lamp is a very low pressure mercury-vapor gas-discharge lamp that uses a fluorescence to produce visible light. The electric current (in the gas) excites mercury vapor which produce short-wave ultraviolet light that then causes a phosphor to fluoresce, producing visible light. A fluorescent lamp converts electrical power into useful light much more efficiently than incandescent lamps. The most popular fluorescent lamps used for plant growth are T5 Fluorescents and Compact Fluorescents. When comparing the two of equal wattage, the T5’s are better for spreading out the light and covering a larger area more evenly. This is ideal for many small plants such as seedlings or cuttings. The CFL is better for covering a smaller area more intensely, which would be better for growing fewer, larger plants. When comparing Fluorescent lighting to other types of pant lighting, Fluorescents tend to excel at growing seedlings and cuttings as well as any plant with a low light requirement. Although possible, flowing fruits and vegetables is generally more successful with a higher intensity lamp.

Do I need a reflector?
Generally speaking a reflector is a must to ensure that all of your light is director towards your plants. Since lamps often produce light in a 360 degree pattern from the center of the lamp, it is especially important in horizontal applications to direct the light sent upward back down towards the canopy. A different style of growing employs the use of HID lamps hung vertically between taller plants. Since the lamp is hanging at approximately half way up the height of the plant and is surrounded by plants on all sides the reflector is not required. This is the only style of growing that will not benefit from the use of a high quality reflector.

What is an Induction Lamp and what is it good for?
An electrode less lamp or induction light is a light source in which the power required to generate light is transferred from outside the lamp envelope to inside via electromagnetic fields, in contrast with a typical electrical lamp that uses electrical connections through the lamp envelope to transfer power. There are three advantages of eliminating electrodes: • Extended lamp life, because the electrodes are usually the limiting factor in lamp life. • The ability to use light-generating substances of higher efficiency that would react with metal electrodes in normal lamps. • Improved collection efficiency because the source can be made very small without shortening life, a problem in electroded lamps Induction lamps are ideal for applications where low heat output and highly efficient lighting are required. Induction lamps provide similar light output to a standard fluorescent, except with a more optimized spectrum for plant growth and come in much higher wattages. Although initially a 400w Induction Lamp may appear to have similar performance to 400w of T5 Fluorescents (both producing approx 40 000 Lumens) the differences become evident very quickly. Induction lamps are rated for 10 x the bulb life than a T5 Fluorescent. This means the difference between 10 000 hours and 100 000 hours of bulb life. The induction lamp also maintains 90% of its light output over 70 000 hours. Like other fluorescent technologies, the induction lamp is not a High Intensity Discharge lamp, which means it produces its light over a larger surface area instead of being very intense in one hot spot. This means these lights evenly light a large area much more effectively than an HID lamp would. Huge savings can be realized when comparing to HID lighting by producing similar or higher light levels over a larger area while consuming less than ½ the wattage. (400w induction vs. 1000w HID.) The ideal distance between an induction lamp and plants is 6” vs. 18” for a 1000 HID. This means these lights excel at growing many short plants vs. few taller plants. Modern greenhouses are starting to employ the use of Induction lighting due to their excellent efficiency and length of operation.

Is it safe to run a 1000w Lamp on my homes current wiring?
Without knowing your particular electrical situation we cannot provide you with a definite answer. A qualified electrician should always be consulted when you are unsure of your wiring. Assuming your home is up to current electrical codes, assuming you have nothing else running on the circut, a 1000w HID would run safely on a standard 15 amp circut. A 1000Watt Light will use around 10 amps of electricity. Generally speaking, a standard household circuit in North America consists of 14 gauge wire rated for 15amps and 120v. Assuming that your 1000w light is the only thing plugged into that circuit, you will be drawing roughly 9.7 amps on the 15 amp circuit. This is below the 80% maximum load one should place on any electrical circuit and you would be safe to run your lamp. Exceeding the 80% capacity of any electrical circuit is not recommended and may be a fire hazard.

What is Metal Halide lighting and what is it good for?
A metal-halide lamp is an electric light that produces light by an electric arc through a gaseous mixture of vaporized mercury and metal halides[1][2] (compounds of metals with bromine or iodine). It is a type of high-intensity discharge (HID) gas discharge lamp. Developed in the 1960s, they are similar to Mercury vapor lamps, but contain additional metal halide compounds in the arc tube, which improve the efficiency and color rendition of the light. Metal halides are extremely efficient at producing light in the white and blue color range. These types of light have an ideal effect on vegetative plants. Using a metal halide for vegetative growth will produce short and bushy plants with extremely tight internodal spacing. The downsides to Metal Halide lights would be high operating temperature making exhaust fans or air cooled light fixtures a requirement, short bulb life (5-15 000 hours) and a rapid decrease in light output over the life of the lamp.

What is a relay or a flip box?
Relays or Flip boxes allow gardeners to divert the power from one ballast to a second reflector/lamp when the primary reflector/lamp is not in use. This means you can run your lamp and reflector for 12 hours and then use the relay to switch to a second garden for 12 hours. The benefit of these systems is doubling your garden space without purchasing a second set of ballasts. All that is required is a second lamp cord, reflector and lamp. Your ballast will run for 24 hours a day between both gardens. This does not work for 18/6 light schedules.

What is L.E.D. Lighting and what is it good for?
An LED lamp (or LED light bulb) is a solid-state lamp that uses light-emitting diodes (LEDs) as the source of light. LED lamps offer long service life and high energy efficiency, but initial costs are higher than those of fluorescent and incandescent lamps. Chemical decomposition of LED chips reduces luminous flux over life cycle as with conventional lamps. In regards to plant growth, LED grow lights employ the use of diodes producing only the specific wavelengths of light required for plant growth. This results in an extremely efficient grow light which can produce tremendous growth with minimal wattage. This makes LED grow lights ideal for situations where low temperatures and high efficiency are a must. In small scale gardens where it is difficult to run a HID lamp due to excessive heat, LED grow lights are a viable alternative. Modern greenhouses are starting to employ the use of LED lighting due to their excellent efficiency and length of operation.

Are there controllers available to run multiple HID lamps from one power source?
Yes, gardeners can purchase pre-made lighting controllers that require a dedicated wire to an electrical panel or other high power outlet (dryer or stove outlets). This allows you to plug your multiple hid lamps into one controller and use one timer to control the light schedule of all of your lights. This is the simplest way for a gardener to run multiple HID lamps. These Power Boxes can be purchased at any Homegrown Hydroponics location.

What is Sulphur Plasma lighting and what is it good for?
The sulphur-plasma lamp is a relative newcomer, but it shows some promise where very high intensity lighting is needed. The primary light source is a small quartz bulb with a few milligrams of sulphur inside (along with an inert gas – typically argon or xenon), and this is subjected to intense bombardment with microwave energy. After a few seconds, the sulphur starts to convert to the fourth state of matter – plasma. Full intensity is reached in less than 5 minutes. The plasma principle is used for most HID lamps, except that the others (metal halide, mercury vapour, high pressure sodium, etc.) use electrodes inside the tube, rather than bombarding the active material with microwave energy. Ultimately, it is largely the erosion of the electrodes (along with possibly broken high pressure seals between the envelope and the electrode lead-in wires) that signals the end of life of a typical plasma light source. • Sulphur bulbs are twice as efficient as other sources of high quality white light. • They produce almost no ultraviolet light and very little infrared; this makes them easier to use with plastic fixtures or fibres. • The full-spectrum light that is produced is extremely good for visual acuity and feels much like sunlight. • The bulb is very simple, a hollow quartz sphere with sulphur and argon gas, and so it is environmentally benign and does not degrade in use. • The light source is very bright so the light can be efficiently distributed over large spaces. • The light output and colour does not degrade over time, and it is fully dimmable down to 30%. The downside to Sulphur Plasma lighting is that it is cost prohibitive. With many companies failing to successfully launch this new technology, the high cost (approximately $3500 per 1000w unit) is surely a huge factor.

Is it safe for my eyes to look at grow lights?
No, one should never look directly into a grow light. This can cause serious injury to your retina. It is however acceptable to work in areas lit by HID lighting. Some gardeners feel their eyes become strained after prolonged exposure to HID light environments. All gardeners would benefit from eye protection when working around indoor grow lights. The benefits are protecting your eyes from damaging UV rays as well as correcting the color emitted by HID lights to a more natural appearance for easier disease pest identification. The sooner the gardener can spot problems, the more effectively they can be dealt with. One ounce of prevention is worth a pound of cure! Method Seven protective eye wear is available at all Homegrown Hydroponics locations.

How much light do I require?
Plants with the highest light requirements will grow best with HID light levels between the ranges of 40w-75w per square foot of garden area. This means that when using a Metal Halide or High Pressure Sodium grow lamp the gardener would use: 1000w to cover a 4’x4’ area. 1000w/16 sqft = 62.5 w/sqft 600w to cover a 3’x3’ area. 600w/9 sqft = 66.7 w/sqft 400w to cover a 2.5’x2.5’ area. 400w/6.25 sqft = 64 w/sqft. In confined spaces such as grow tents; gardeners will often go one size down in order to more easily keep temperatures in the desired range for optimal plant growth. I.e. 2 x 600w in a 4’ x 8’ tent rather than 2x 1000w. Some plants (especially the non flowering varieties) can grow fine with 20-45 watts per square foot. When calculating the required amounts of fluorescent lighting for seedling, cutting or any vegetative growth of small plants, roughly half of the recommended HID wattage is required to promote this early growth. I.e. 400w t5 fluorescents over a 4’x4’ area.

How do I dispose of old grow lamps?
Due to the contents of hazardous metals found in grow lamps, they should be recycled properly by taking them to your local recycling depot. Some hydroponic stores will recycle them for you as well. Grow lamps should not be placed in the garbage as they are likely to break and leak their contents into the ground at the landfill.

How long should I leave my grow lights on for?
Some gardeners like to leave their lights on for 24 hours to get maximum growth. However, by far the most popular light duration for vegetative plants is 18 hours on and 6 hours off. This schedule will mimic a day of full sunshine followed by a natural dark period. Using this method will save the gardener electricity while still providing exceptional growth. Some plants are triggered to flower by a reduced duration of daylight. These plants can be tricked indoors into producing their flowers with a reduction of light duration. To achieve this, most gardeners will reduce their light to 12 hours on and 12 hours off. Other plants simply flower then they are mature and can benefit from the 18 hours of light throughout their life.

How far should my light be from my plants?
Low heat grow lights such as fluorescent and induction lamps should be kept approximately 6” from the tops of plants for optimal growth. LED grow lights can usually be kept at a distance of 9”-12” from the tops of plants for optimal growth. 400w HID should be kept at a minimum of 12”-16” inches from the tops of plants for optimal growth. 600w HID should be kept at a distance of 16”-20” inches from the tops of plants for optimal growth. 1000w HID should be kept at a distance of 18”-24” inches from the tops of plants for optimal growth. Often lamps used in conjunction with an Air Cooled Reflector can lead to a decrease in distance required distance between lamp and plants. Using ones hand at plant height to determine the amount of heat between the lamp and the plant is an effective tool at gauging light heights. If the temperatures are comfortable for your hand then they are comfortable for the plants.

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