Light height

I have a single 1000-watt and two 400-watt HPS lamps, as well as two four-foot, two-tube fluorescent fixtures. How far above the plants should I hang the lamps?
Chief NastyNug,
Nixa, Missouri

Under most circumstances a 1000-watt lamp with no shield should be kept no less than two feet from the top of the canopy. A 400-watt lamp can be placed as close as 15 inches. A fluorescent tube can be placed about six inches from the top of the plant.

The distance is not to protect the plants from the lamp’s brightness, but from the heat that it generates. At its peak, the Sun is brighter than even 1000-watt lights. The amount of light measured 24 inches directly under a 1000-watt horizontal HPS lamp with high efficiency reflector measured about half of what a plant would receive at noon on a cloudless day in early July at the 38th parallel. It would equal the light intensity of a September day at noon, when the flowers are ripening. There was fall-off as the meter was moved from the center.

Heat from the lights causes the buds to “run.” Instead of blocky buds on compact stems, the branches stretch and new growth appears, with thin groups of flowers. There are several ways to deal with the heat. Swift circulation/ventilation systems can be set up to move heated air away from the canopy and out of the area. This works best when there is a constant source of cool air. For instance, in Holland, which has cool air most of the time, heated air is replaced with a constant flow of filtered street air. In large spaces the air draft results in a low roar of white noise.

Another method of dissipating the heat is to use a light mover. The heat is radiated to any point for only a few moments. The mover disperses both light and heat. With a reasonable circulation system, the heat is variable, but not intense.

By far the most efficient method of eliminating the heat, enabling the lights to be placed closer to the plants, is by using air-cooled lights. The lights are enclosed by the reflector, which holds a glass plate that captures most of the lamp’s heat. Using 4-inch duct tubing powered by an inline fan, the lights draw in cool air from outside the space to cool the light. Heated air is pushed out through the exhaust duct on the other side of the reflector. This air has never been in contact with the garden. It has no odor, just heat. It can be used to heat a space or just vented to the outdoors.

With air cooling, a 1000-watt lamp can be placed at 15-18 inches from the top of the canopy and a 400-watt lamp can be placed about 12 inches above it.

Readers with grow questions (or answers) should send them to Ed at: Ask Ed, PMB 147, 530 Divisadero St., San Francisco, California 94117, USA
You can also email Ed at [email protected], and send queries via his website at www.ask-ed.net.
All featured questions will be rewarded with a copy of Ed’s Marijuana Question? Ask Ed. from Quick Trading.
Sorry, Ed cannot send personal replies to your questions.

Comments

231 Comments

  1. Pingback: http://bit.ly/hawaii-seo

  2. Pingback: Diet

  3. Pingback: Berdion de Crudo

  4. Pingback: دانلود فیلم رگ خواب

  5. Pingback: Google spam tactics

  6. Pingback: avakin life hack android

  7. Pingback: what is mlm company

  8. Pingback: دانلود فیلم رگ خواب

  9. Pingback: zenofem reviews

  10. Pingback: www.consumerhealthdigest

  11. Pingback: marks and spencer coupon

  12. Pingback: menoquil review

  13. Pingback: prostara review

  14. Pingback: Oddsmonkey

  15. Pingback: Oddsmonkey

  16. Pingback: Oddsmonkey

  17. Pingback: Oddsmonkey

  18. Pingback: Oddsmonkey

  19. Pingback: kitchen cooking

  20. Pingback: best slot machines to win on

  21. Pingback: ΚΟΥΠΟΝΙ ΣΤΟΙΧΗΜΑ

  22. Pingback: buy hacklink

  23. Pingback: ATHENS HOTELS

  24. Pingback: my site check here

  25. Pingback: go here to seee the asite

  26. Pingback: پنجره

  27. Pingback: Taruhan Olahraga

  28. Pingback: فیلم نهنگ عنبر

  29. Pingback: porn movie

  30. Pingback: xxx mobi

  31. Pingback: game hack

  32. Pingback: https://www.youtube.com/watch?v=GPJYH7LYunc

  33. Pingback: Sang Kutu Bola

  34. Pingback: Deal Feed

  35. Pingback: Taruhan Olahraga

  36. Pingback: Schluesseldienst

  37. Pingback: link

  38. Pingback: SkinAlley

  39. Pingback: Shopping cart cover

  40. Pingback: gosexy

  41. Pingback: Limo Rental Vancouver BC

  42. Pingback: real caller apk

  43. Pingback: baby shower gift ideas

  44. Pingback: دانلود فیلم نهنگ عنبر

  45. Pingback: stroller accessories

  46. Pingback: headhunter

  47. Pingback: دانلود سریال شهرزاد فصل دوم

  48. Pingback: دانلود فیلم دوبله شده

  49. Pingback: دانلود آینه بغل

  50. Pingback: پنجره کرج

  51. Pingback: he said

  52. Pingback: پنجره

  53. Pingback: aries man in love with me

  54. Pingback: click terminal

  55. Pingback: Judi Online

  56. Pingback: Private Tour

  57. Pingback: youtube video

  58. Pingback: physics solution manual

  59. Pingback: Judi Online

  60. Pingback: google leaks

  61. Pingback: vehicle shippers

  62. Pingback: دانلود فیلم نهنگ عنبر 2

  63. Pingback: vape mods

  64. Pingback: Easiest Way To Make Money Online

  65. Pingback: recruitment

  66. Pingback: Watch movie for free

  67. Pingback: Judi Online

  68. Pingback: Bad Credit Remortgages

  69. Pingback: read now

  70. Pingback: real estate theme wordpress premium

  71. Pingback: garden

  72. Pingback: دانلود فیلم

  73. Pingback: download

  74. Pingback: Cash Offer

  75. Pingback: download movie

  76. Pingback: دانلود

  77. Pingback: دانلود فیلم

  78. Pingback: steel chips dip bowl

  79. Pingback: karaj

  80. Pingback: kitchen tools stainless

  81. Pingback: real casinos online

  82. Pingback: صيانة

  83. Pingback: 192 168.0 1 alterar senha wifi

  84. Pingback: gay porn

  85. Pingback: vlogging camera

  86. Pingback: picture

  87. Pingback: usi tech presentation

  88. Pingback: slimming pants

  89. Pingback: gardening

  90. Pingback: Finger Family Song

  91. Pingback: top 40 music

  92. Pingback: http://mylink1257.skyrock.com/3299928498-l-oreal.html

  93. Pingback: Seo

  94. Pingback: پنجره دوجداره

  95. Pingback: EVA TV

  96. Pingback: atualizado

  97. Pingback: پنجره

  98. Pingback: پنجره دوجداره

  99. Pingback: Web Design Yakima

  100. Pingback: award winning movie

  101. Pingback: have a peek at this web-site

  102. Pingback: heartland dental care

  103. Pingback: Data Logger

  104. Pingback: window

  105. Pingback: ed sheran

  106. Pingback: walmart1 login

  107. Pingback: stainless steel shower head

  108. Pingback: https://www.pinterest.com/adulttoys4427/

  109. Pingback: grafisch.LinkenOnline.nl

  110. Pingback: site web

  111. Pingback: garden bridges san francisco

  112. Pingback: مشاوره بازاریابی اینترنتی

  113. Pingback: Weed Shop

  114. Pingback: google hd porn

  115. Pingback: پنجره دوجداره

  116. Pingback: اموزش ساخت پنجره دوجداره

  117. Pingback: پنجره دوجداره

  118. Pingback: gernas kids

  119. Pingback: پنجره دوجداره

  120. Pingback: دانلود

  121. Pingback: پنجره دوجداره

  122. Pingback: gratis annonser dk

  123. Pingback: پنجره

  124. Pingback: پنجره

  125. Pingback: دانلود فیلم ایرانی

  126. Pingback: پنجره دوجداره

  127. Pingback: Pay Per Click Belfast

  128. Pingback: fast loans uk

  129. Pingback: mon id�e

  130. Pingback: Limo Service Vancouver BC & Party Limos Bus Vancouver BC

  131. Pingback: free delivery codes

  132. Pingback: callaway x2 hot driver australia

  133. Pingback: make money online

  134. Pingback: شرکت تولیدی پنجره دوجداره

  135. Pingback: دانلود

  136. Pingback: قیمت پنجره دوجداره

  137. Pingback: پنجره ضد سرقت ایرانی

  138. Pingback: دانلود فیلم

  139. Pingback: فروش توری پنجره دوجداره

  140. Pingback: آموزش ساخت پنجره دوجداره

  141. Pingback: پنجره دوجداره ویستایست

  142. Pingback: Marquees London

  143. Pingback: game

  144. Pingback: guia consulta cpf

  145. Pingback: political polls twitter

  146. Pingback: Best Crib Mattress

  147. Pingback: دانلود

  148. Pingback: 食品

  149. Pingback: دانلود سریال عالجناب اول

  150. Pingback: دانلود فیلم ایرانی

  151. Pingback: دانلود سریال عالیجناب قسمت اول 1

  152. Pingback: دانلود شهرزاد قسمت 16

  153. Pingback: 16 دانلود سریال شهرزاد

  154. Pingback: youtube

  155. Pingback: Kasha

  156. Pingback: Roof Repair Long Island

  157. Pingback: blazing key

  158. Pingback: ΤΣΑΝΤΕΣ TRUSSARDI

  159. Pingback: Social Media Marketing

  160. Pingback: Accounting firms in chicago

  161. Pingback: clash royale gems tool

  162. Pingback: دانلود سریال شهرزاد قسمت 15 پانزده

  163. Pingback: anime

  164. Pingback: titleist 917 driver

  165. Pingback: vpm

  166. Pingback: nico control � bom

  167. Pingback: دانلود قسمت هشتم شهرزاد دوم

  168. Pingback: la home

  169. Pingback: DraftKings DFS

  170. Pingback: coin-banks bitcoin

  171. Pingback: My Homepage

  172. Pingback: bitcoin trading

  173. Pingback: brief boxer gay

  174. Pingback: پنجره دوجداره

  175. Pingback: clash royale gems tool

  176. Pingback: video gaming

  177. Pingback: cliquez ici

  178. Pingback: dick

  179. Pingback: compare hotel prices website

  180. Pingback: Roof Repair Long Island

  181. Pingback: casino games usa

  182. Pingback: دانلود قسمت ششم شهرزاد دوم

  183. Pingback: groin support

  184. Pingback: دانلود موزیک

  185. Pingback: Facial Spa Services Hollywood

  186. Pingback: Facial Spa Services Cooper City

  187. Pingback: Facial Spa Services Oakland Park

  188. Pingback: دانلود قسمت هفدهم عاشقانه

  189. Pingback: شرکت تولیدی پنجره دوجداره

  190. Pingback: فروش پنجره دو سه جداره

  191. Pingback: دانلود سریال عاشقانه

  192. Pingback: پنجره دوجداره وین تک

  193. Pingback: ساخت پنجره دوجداره

  194. Pingback: porno gratis

  195. Pingback: videos porno

  196. Pingback: videos porno

  197. Pingback: porno

  198. Pingback: videos porno

  199. Pingback: videos porno

  200. Pingback: porno

  201. Pingback: porno gratis

  202. Pingback: videos porno

  203. Pingback: porno gratis

  204. Pingback: Admission via Good Donation in any medical college

  205. Pingback: porno

  206. Pingback: ping g30 driver australia

  207. Pingback: دانلود قسمت اول فصل دوم شهرزاد

  208. Pingback: nba jerseys melbourne

  209. Pingback: bypass windows 7 admin password

  210. Pingback: دانلود قسمت یازدهم شهرزاد دوم

  211. Pingback: دانلود ققسمت 12 عاشقانه

  212. Pingback: دانلود قسمت پنجم شهرزاد دوم

  213. Pingback: Loyola College for Sale

  214. Pingback: دانلود سریال عاشقانه

  215. Pingback: popular online twshows

  216. Pingback: Paleo Diet

  217. Pingback: April O'Neil

  218. Pingback: دانلود قسمت هفدهم عاشقانه

  219. Pingback: دانلود قسمت دهم فصل دوم شهرزاد

  220. Pingback: دانلود قسمت ششم فصل دوم شهرزاد

  221. Pingback: lesbian sex

  222. Pingback: قیمت پنجره

  223. Pingback: دانلود شهرزاد قسمت نهم فصل دوم

  224. Pingback: دانلود شهرزاد قسمت هفتم فصل دوم

  225. Pingback: دانلود قسمت هشتم شهرزاد دوم

  226. Pingback: دوم 2 دوم 2 دوم 2 دوم 2 دوم 2 دوم 2 دوم 2 دوم 2 دوم 2 دوم 2 دوم 2 دوم 2aaadffdsvc

  227. Pingback: alcohol abuse treatment

  228. Pingback: دانلود رایگان قسمت 8 هشتم سریال شهرزاد فصل دوم 2

  229. Pingback: 4cyn5et4m5t94c5t9m4vn54cx65

  230. Pingback: Under Canopy Lighting Cannabis

  231. Anonymous on

    k i have a 150 watt light it will do for now, first time growing. i want to kno wats the right height i shud move the light up with the plant. 12 inches? more or less? one of the plant leaf looks like its folding a bit wats that a sign of? thx