FLUORESCENT LIGHTS: Footcandles At Various Distances

Culture Orchid Doctor

by Robert M. [Bert] Hamilton (Compiler)

Originally published in The Orchid Doctor in 1980 and 1988

Posted by Sys Admin over 6 years ago.

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Illumination reduces quickly on increasing inches distant from lamps; examples: one inch from two lamps gives 1,1OOfc.; at three inches 680fc.; at six inches 420fc.; at nine inches 300fc. US Dept. of Agriculture. Yearbook, 1973, adapted by RMH
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Fluorescent Lights Comments
FLUORESCENT LIGHTS: Ballasts Higher priced fixtures have ballasts which are rated at .85 amps, the cheaper ones are rated at .675 amps, or 30% less light, regardless of the type of bulb used, so take a good look before you buy. OIE87Jan-l 0
FLUORESCENT LIGHTS: Best Height Above Cattleyas Two inches; prop up the small plants. A70-427; A75-298 0
FLUORESCENT LIGHTS: Cattleya Types Produce Only Vegetative Growth Keep night temperatures to 60-62 deg.F. and days to 78-85 deg.F., with not more than 13 hours light. A69-424 0
FLUORESCENT LIGHTS: Cost of Electricity In 1977 the monthly cost for electricity was about $3.84 for four tubes burning 16 hours a day, with space for 50 plants. A77-897 0
FLUORESCENT LIGHTS: Details The life expectancy on a one-only start of a lamp is 18,000 to 20,000 hours; with a daily on/off routine the expectancy is 12,000 hours in three years; the initial brightness diminishes rapidly for the first nine days and then tapers off; a black ring forms at one or both ends of the tube and indicates about 85% of the lamp life; most efficient is the cheapest, the cool-white, but the others have beneficial character istics which may be what you are looking for. OIE88Jan-8 0
FLUORESCENT LIGHTS: For Paphiopedilums Two 48" Wide Spectrum, with two 48" cool-white tubes and with four 25-watt incandescents in one reflector gives 1,000 fc. five inches from the tubes; with 13 to 15 hours per day as adequate for paphiopedilums. A74-792 0
FLUORESCENT LIGHTS: Generate Too Much Heat Rewire the ballasts outside the closet; or, any fan in use must not only circulate air but ventilate to an outside source of cool air. A72-1003 0
FLUORESCENT LIGHTS: Growing Under Three set-ups are described: Four daylight tubes with two 60W incandescents as a group. 2, Chroma 50's which simulate a summer sunshine-for colour and costs about the same as for daylight tubes, and three. Chroma 75's, which simulates a north sky light; plants grew better under them than under expensive growing lamps. Ca82(7)-20 0
FLUORESCENT LIGHTS: How Effective Are the Twisted Ones? Light is produced by the molecule in gas rubbing against each other and the more tube surface, the more light that is visible; twist-types have their surface area increased by 15 to 25%. A83-343 0
FLUORESCENT LIGHTS: How Many Tubes for Bench Width? Not less than one tube for every four inches of width; for a two-foot wide bench use six fluorescent tubes. ODA75(4)-38 0
FLUORESCENT LIGHTS: Indoor Culture A review of 47 papers on growing under lights which appeared in the American Orchid Society Bulletin; refer to A77-318 0
FLUORESCENT LIGHTS: Minimum Requirements In a 3ft. x 3ft. x l8in. cabinet: two 3-ft. tubes placed nine inches apart; for high-light requiring plants: three 3ft. tubes which equals 90 watts for cattleyas, encyclias, oncidiums, dendrobiums, odonts. etc. OR84-44 0
FLUORESCENT LIGHTS: Mixed Tubes Cool-white with Gro-Lux, also Natur-Escent and Gro-Lux in a 1:1 ratio; four 40-watt tubes over 2 ft. X 4 ft. area is adequate light for cattleyas, miltonias, paphiopedilums and phalaenopsis. A66-926; A72-204 0
FLUORESCENT LIGHTS: Optimum Amount for Seedlings in Flasks 40 watt per square foot at twelve inches distance is abundantly adequate. A74-969 0
FLUORESCENT LIGHTS: Preferred Types to Use for Cattleyas Gro-Lux is not strong enough; try wide-spectrum Gro-Lux; or, use regular fluorescent or V.H.0. type fluorescents; supplement with 25% incandescent, i.e. 50, 75 or 100 watts. A71-1021 0
FLUORESCENT LIGHTS: Selection A guide to much data on spectral distribution; alternate arrangements of lamp combinations; comparison of 40-watt whites; comparison of five horticultural lamps with cool-whites; comparison of 50 lamps; power consumption and sound rating; refer to A79-566+ 0
FLUORESCENT LIGHTS: To Produce Excellent Color in Flowers For display, the odd combination of one standard (not wide-spectrum) Gro-Lux tube #F40/GRO, with one Cool White Deluxe tube #F40/CWX (not the standard Cool White tube); under them white is pure white, greens are excellent, and yellows and lavenders also; purples have a pleasing slight reddish tinge; Design White #F40T12/SGN is also good for display. OD69-95 0
FLUORESCENT LIGHTS: Turning on in Living Room Area Where Plants Also Grow Probably no photoperiod effect; fluorescents are not very effective for photoperiod control; the 15 to 30 fc. emitted at a distance would not affect Den. phalaenopsis. A73-888 0
FLUORESCENT LIGHTS: Two-tube 48" Fixture Gives inadequate (600-800 fc.) lighting two to three inches from plants; a four-tube 48" gives 800-1,000 fc. four to six inches away. A78-226; eight tubes for 16 square ft. recommended, with a 60-watt incandescent lamp. A62-383+; A62-478+; A64-590; A68-431 0
FLUORESCENT LIGHTS: Types Available A review of kinds of tubes: Cool White; Daylight; Warm White; Gro-Lux; Vita-Lite; Verilux; High Output; Super High Output; High Intensity Discharge; refer to A75-292+ 0
FLUORESCENT LIGHTS: Types Used One grower uses half Gro-Lux Wide Spectrum and half Vitalite Power Twist. OIE85Jan-13 0
FLUORESCENT LIGHTS: Vitalite Power Twist Main types of plants can be flowered under them if placed as close to the bulbs as possible without burning for these hours: 16 to 18 in summer; 14 to 16 in spring and fall; ten to 12 hours in winter. A85-193 0
FLUORESCENT LIGHTS: Wattage Per Square Foot Tubes 12 inches above the leaves provided 20 watts, barely enough to satisfy phalaenopsis; six tubes arranged in a dome shape supplied 30 watts; a VHO-fixture having the intensity of three normal tubes provided 45 watts; lamps lose 10% during the first few weeks of their service and 30% by the end of the first year. OIE87Mr-12 0
FLUORESCENT LIGHTS: Weak Some stores sell cheaper units made in Taiwan and elsewhere which deliver only 300 foot-candles compared with the normal 800 fc required by plants. OIE85Jn-4 0
FLUORESCENT LIGHTS: Why Not Place Vertically? They will operate that way but the leaves' cells display more chlorophyll on the upper surface, and derive more stimulus. A74-300 0

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