B-high Posted August 26, 2011 Share Posted August 26, 2011 hi gyuys can someone xeplain these mh/hps lights thing 2 me please cause its all double duch to me sorry are they the same as sodium lights if not what are they and what watt do i need Metal halide / high pressure sodium Link to comment Share on other sites More sharing options...
ProfDank Posted July 16, 2012 Share Posted July 16, 2012 light intensity virtually doubles every 6 inches closer a HID is to the canopy of bud light adheres to the "inverse square rule" ,i.e it diminishes to the square of the distance ,which can mean you may be losing a lot of your lights potential , always make sure your lights are at the right height to provide maximum lumens but not too close incase of heat and not to far away because it will be less efficient here is a rough rule of thumb for lights hang 1000w and 600w HID's 24-36 inches from canopy hang 400w HID's 18-24 inches from canopy and smaller HID's to 6-12 inches away peace Also use the hand, iows slowly raise your hand until it feels too hot, if its too hot for you it is for the canopy as well, use this as the clossest you can get w/o burning etc, I also have a oscillating fan blowing between the light and canopy. Link to comment Share on other sites More sharing options...
iBMe Posted September 16, 2012 Share Posted September 16, 2012 nice, tip. just to add to it; the best practical lighting combination for flowering is generally considered to be a 2:1 ratio of hps:mh. the mh helps make he buds moe dense and solid than with solely hps lighting. That's an interesting tip thanks il look into that. Does the MH produce more blue light or?? I was thinking about getting a 150w blue cfl to go in there as I have read blue encourages trichome production. What are MH's like for heat? more than a HPS or about the same? Link to comment Share on other sites More sharing options...
wu-tang-sam Posted September 17, 2012 Share Posted September 17, 2012 nice, tip. just to add to it; the best practical lighting combination for flowering is generally considered to be a 2:1 ratio of hps:mh. the mh helps make he buds moe dense and solid than with solely hps lighting. That's an interesting tip thanks il look into that. Does the MH produce more blue light or?? I was thinking about getting a 150w blue cfl to go in there as I have read blue encourages trichome production. What are MH's like for heat? more than a HPS or about the same? It's the uv light from the halides that promote the resin production afaik, so the cfl wouldn't cut it. Halides run a little warmer, my 400 halide gives out about the same as my 600 pure sodium Link to comment Share on other sites More sharing options...
BiGbuDDahLuvA Posted September 17, 2012 Share Posted September 17, 2012 i dont know the answer to this so im not being cheeky, but wouldnt more blue than red spectrum light influence just foliage growth? i think the 2- 1 ratio suggested above sounds the right idea. Link to comment Share on other sites More sharing options...
wu-tang-sam Posted September 17, 2012 Share Posted September 17, 2012 i dont know the answer to this so im not being cheeky, but wouldnt more blue than red spectrum light influence just foliage growth? i think the 2- 1 ratio suggested above sounds the right idea. I think people get too hung up on spectrums personally, both halide and hps are pretty crap in terms of PAR. Some report more "leafy" growth with the blue fluros or halides, or even the dual specs,but it's negligable imo, especially during the latter 2 weeks of the plant's life as we're discussing here Link to comment Share on other sites More sharing options...
Trashedagain77 Posted September 7, 2020 Share Posted September 7, 2020 On 03/03/2002 at 8:31 AM, Arnold Layne said: Yes D.o.c., absolutely correct. Also it helps to rotate the plants under the light, both on their own axis and around the growing area. This way every plant gets equal quantities of light throughout its Flowering period. It is unreal how many grows are "stationary", with plants huddled around the edges and struggling. With rotation I am happy at 35 watts per sq.ft, well below the suggested 50! I have not noticed any yield deficit however. Use that light!!! :mad: Hi Arnold this seems a reasoned suggestion about rotation but I have read somewhere, I think one of the old bibles about a topic on "negative triopism", which if I remember claimed it to be negative to move plants or even rotate them especially once flowers begin showing as the plants form a natural canopy through competition and that by moving plants that this will negatively affect their best attempts to maximise their performance. This is only something I remember reading Arnold and I am certainly not disagreeing with such a knowledgeable member as yourself. Just interesting stuff. Thanks 1 Link to comment Share on other sites More sharing options...
photobat Posted March 11, 2021 Share Posted March 11, 2021 Omg don't say that otherwise @Arnold Layne might feel like he has been breaking his back for the last 19 years for nothing !! Better late than never i suppose , i'm more of the mind set that a little rotation helps to even things out and keep a more even canopy and helps with distances between plant and lamp. being hydro i don't like leaving the roots in the light for long at all when lifting inner pot out and replacing elsewhere in the room, so i get on with it as faster than a dope head on a moped !! 2 Link to comment Share on other sites More sharing options...
Arnold Layne Posted March 11, 2021 Share Posted March 11, 2021 Whatever works for you, works! In the end, there's as many ways to do this as there are growers a growing 5 Link to comment Share on other sites More sharing options...
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