Distance of Lights to Plant?

I just put my 600w M.H light on my plants today they were under 24 hr fluoros how far should i keep the light from my plant I have 4 under it now and am doing 18-6 any advice???

Typically for 600w you would want to keep it 18 inches away.

even after just putting them under from using the fluorescents? or should i gradually lowere it? it will not be to much of a shock will it?

chettersbud1 said:

even after just putting them under from using the fluorescents? or should i gradually lowere it? it will not be to much of a shock will it?

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Shouldn't be if there isn't a heat issue. Always check the distance of the light with the back of your hand, if it's to hot for you, it's too hot for your plants.

cool i think i got them about 2 feet rite now I have a air cooled hood but need to get my fan in it wich would allow me to lowere even more and i did the back of hand test and it was not to hot i just used to of my house fans and pointed them up towards the glass I am excited to see the difference betwen the fluoros that i used for the first 2 weeks

Seriously go from flores 20" away then every second day lower 3" till your about 14 " away i run 10,000 watts hordilux superblue and run them 14 " away from plants

rule of thumb is if you hand can handle the heat so can the plants i just got 2390 grams per 1000 watt dry keeping my lights low as possible

420God's advice was spot on.

thexception said:

420God's advice was spot on.

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why would you say he is spot on ???? usually when you switch to flower most common grower will have his lights up higher this is in realitly not a good way being there is a serious growth spurt and what happens here is that your plant stretches and your buds dont join so when trim time comes your big bud your cutting lower parts of it cause they didnt join up what i found is keeping lights low as possible this will aloow not such a stretch period of forst 2 weeks of flower givving you one big fckin bud rather then breakin a bud apart cause there stem showing now to each there own but i know one big bud wet when dryed has shriviled up 1/2 to 3 /4 and bottom line thats what people want decent buds not smalll crap that turns into shake

Just thought I'd ask... You say typically a 600W should be around 18" away from the canopy... I have an air-cooled 400W/600W Sun-Systems - Super Sun 2 reflector, the bottom of it is relatively cool to touch.. My question is: Will the actual brightness of the 400W/600W lamp do any harm being closer than 18" away.. Say between 3" and 12" ?? Heat is not an issue. I can run the lamps COLD if need be.. But I really want to know if anything to do with light intensity, Lumens, Radiation, PAR, etc etc will harm my girls in any way - being at pretty much touching distance ??

And is there any bennifit from getting the reflector as low as possible, say within an inch of the canopy ??

Any and all factual replies will be REP'D! many thanks - STELTHY

dude closer the better no matter what if you got no heat issues your laughin then no shit i run 1000 wattters around 14" from my canvas

stelthy said:

Just thought I'd ask... You say typically a 600W should be around 18" away from the canopy... I have an air-cooled 400W/600W Sun-Systems - Super Sun 2 reflector, the bottom of it is relatively cool to touch.. My question is: Will the actual brightness of the 400W/600W lamp do any harm being closer than 18" away.. Say between 3" and 12" ?? Heat is not an issue. I can run the lamps COLD if need be.. But I really want to know if anything to do with light intensity, Lumens, Radiation, PAR, etc etc will harm my girls in any way - being at pretty much touching distance ??

And is there any bennifit from getting the reflector as low as possible, say within an inch of the canopy ??

Any and all factual replies will be REP'D! many thanks - STELTHY

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Links for info;

~~~> http://www.thctalk.com/cannabis-forum/archive/index.php/t-28.html

~~~> http://hydroponiccentral.com/?tag=lamp-distance

~~~> http://www.jasons-indoor-guide-to-organic-and-hydroponics-gardening.com/high-pressure-sodium.html

Basically, if you run your lights too close then you're drowning the plant in more light than it can absorb and you risk bleaching the chlorophyll in the leaves.

DrFever said:

why would you say he is spot on ???? usually when you switch to flower most common grower will have his lights up higher this is in realitly not a good way being there is a serious growth spurt and what happens here is that your plant stretches and your buds dont join so when trim time comes your big bud your cutting lower parts of it cause they didnt join up what i found is keeping lights low as possible this will aloow not such a stretch period of forst 2 weeks of flower givving you one big fckin bud rather then breakin a bud apart cause there stem showing now to each there own but i know one big bud wet when dryed has shriviled up 1/2 to 3 /4 and bottom line thats what people want decent buds not smalll crap that turns into shake

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okay well first he is not switching to flower, he is simply going from his florescents to a strong 600w MH lamp. I use a 400w MH and start at 12" & move them closer (but no closer then 6"), with a 600w, I would have done the same start with 18" and move to no closer then 8" above. but the hand test always applies as well as how the plant reacts.

stelthy said:

Just thought I'd ask... You say typically a 600W should be around 18" away from the canopy... I have an air-cooled 400W/600W Sun-Systems - Super Sun 2 reflector, the bottom of it is relatively cool to touch.. My question is: Will the actual brightness of the 400W/600W lamp do any harm being closer than 18" away.. Say between 3" and 12" ?? Heat is not an issue. I can run the lamps COLD if need be.. But I really want to know if anything to do with light intensity, Lumens, Radiation, PAR, etc etc will harm my girls in any way - being at pretty much touching distance ??

And is there any bennifit from getting the reflector as low as possible, say within an inch of the canopy ??

Any and all factual replies will be REP'D! many thanks - STELTHY

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Light Distance Plant Chart

Having the light too close can also cause the plant to suffer stress, which in turn can of course lead to low yield & it can break down plant resin, some believe. As well many people think the light too close causes airy buds. some taper off the light & move it away gradually at the end of the flowering cycle to more simulate the season change or end of light to spike MJ into producing more trichs. Of course different strains also react to their light exposure in their own way, some tolerate much more then others. If the light is too close, u could be giving up a lot of the flavor or smell that the strain should produce.

(in my memory from another online source)
Bleaching when it comes to MJ really translates to a plant's inability to photosynthesize fast enough. If light is too intense the plant simply can't keep up. Lack of chlorophyll in a flower essentially means it isn't going to produce much of any kind of terpene profile. & none equates to no trichome coverage.

That is basically why I always use the hand test, the suggestive chart range, & most importantly I watch each strain for their reaction to the light they're receiving, their tolerance for nutes, & every other factor of the grow & then adjusting accordingly.

How does bleaching the leaves effect the plant, if the lamps to close... ?? Will it still function and bud etc..?? Does this apply to all wattage of lamps ?? Many thanks - STELTHY

So would you say with no heat problems at all the best distance to have the lamp/feflector from the top of the canopy is 6"... Is that for optimum performance to get the best from the 600W lamp and reflector ?? How far away would you recommend a 250W and a 400W for optimum performance of lamp and reflector ?? - STELTHY