LED Bulbs and Tubes
Phosphor-coated LEDs produce more of a blue spectrum and peak at about 465 nm.There is a vast array of LED retrofit bulbs packed into a larger bulb that fits in household incandescent screw fittings.
Phosphor-coated LEDs produce more of a blue spectrum and peak at about 465 nm.There is a vast array of LED retrofit bulbs packed into a larger bulb that fits in household incandescent screw fittings.
Phosphor-coated LEDs produce more of a blue spectrum and peak at about 465 nm.
| The small container appears to be “swallowed” by t the giant bud! |
LED tubes are shaped like regular T12, T8 and T5 fluorescent bulbs but the tubes are filled with LED light bulbs. More than 200 LEDs will fit in a 4-foot (?? cm) T12 tube. But not all LEDs are created equally. LED tubes that are filled with little lamps with at least one watt each???, are necessary to provide enough light for plant growth.
An energy efficient 22 watt 4-foot T8 LED lamp produces 1,248 lumens. They do not fit in existing T8 fluorescent fixtures. The flicker-free tubes have a lifetime of more than 50,000 hours.
T8 Red tubes are 660nm and contain 288 LED bulbs. Spectrums can also be split into blue and white with a 50/50 split between lamps of 420nm /5500k and contain 144 red and 144 white LEDs. Some fixtures allow LED tubes to be mixed with T8 fluorescent tubes to improve spectrum.
| This group of plants was grown under LED light and appears about the same as the ones grown under and HID. |
Most often different LED bulbs are combined in a fixture to achieve a specific light spectrum.
A series of individual bulbs can be mounted and hard wired into a single fixture that is square, rectangular or circular. Or the fixture can contain long T12 and T8 glass tubes packed with LEDs.
The most practical fixtures allow individual clusters of LEDs packed in a bulb to be easily replaced. Such fixtures also make upgrading LED bulbs inexpensive.
Can be put much closer to plants which increases intense light plants receive
The tubes run cool and can be placed within inches of plants.
LED vs HID Lamps
| The fixtures above these plants consist of groups of LED bulbs grouped together within a fixture. There are several different spectrums of bulbs contained in each fixture. |
Or the comparison could be more easily done by dividing a 1000-watt lamp into single watts. For example a 1000-watt HPS that produces 140,000 lumens yields 140 lm/W.
There are also a few spectrum details that must be addressed. LED fixtures can contain from a few to hundreds of bulbs. The bulbs can be of many different spectrums. Fixtures are manufactured to include bulbs of different spectrums to provide the highest ratings for plant growth. However, I have had a difficult time finding accurate brilliance tests for LED lamps.
| the branches from several buds were grouped together to make this impressive harvest shot. This is an impressive harvest! |
*See the “Inverse Square Law” earlier in this chapter.
End of Life
LED bulbs have a life of 25,000-50,000 hours and come in a wide range of spectrums. LED bulbs have a life from 25,000 to 50,000 hours or longer. They fail by dimming over time. The bulbs are so new to gardeners that there is no specific information about when to replace them. Many bulbs are packed together in fixtures and a single bulb that fails or is not as bright as others may not affect the overall output of the fixture to warrant replacing. Overall I recommend to replace fixtures when it yields 85-95 percent light output.
Do not worry about tossing out hazardous substances when disposing of LEDs. They contain no mercury to pollute the environment. Bulbs and fixtures can be recycled.
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Check out an interesting video on Youtube, http://www.youtube.com/watch?v=OCXhj0iP0Mc
Marijuana Grow Yields 383.6 Grams from a 345W LED Grow Light consuming 290W of power.
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Soft Secrets
