• Here is a link to the full explanation: https://rollitup.org/t/welcome-back-did-you-try-turning-it-off-and-on-again.1104810/

is there such a thing as too much light. like 2600 w in a 4x6-6 area

pickleman

Well-Known Member
like the title says? i have 2 1000s and 1 600 in a shed i added the 600 cuz the temps were too low and it brought me up to a nice 80ish degrees is there ill effect from too much light even if the plants are not burning?
 

timmythetooth

Active Member
like the title says? i have 2 1000s and 1 600 in a shed i added the 600 cuz the temps were too low and it brought me up to a nice 80ish degrees is there ill effect from too much light even if the plants are not burning?
I have a 400whps in a 1'x3.5' closet. i fill it with plants and they work fine. Probably not helpfull but anyways..:-|
 

Topo

Well-Known Member
From all my research, there is essentially no such thing as to much light unless the babies are burnin'. In college, I did a dorm room closet grow that was underlit, and what a waste of fucking time. Never again. If it weren't for the cops, I'd light up a room so that the Space Shuttle Crew could see it from outer space.

Let there be light!
 

pickleman

Well-Known Member
it has 2 desk fans, one wall mount oscillating fan, 1 squirrel cage, 1 inline duct booster, 1 vortect, 2 inline 1000watt lights and 1 600 watt batwing
 

highpsi

Well-Known Member
From all my research, there is essentially no such thing as to much light unless the babies are burnin'.
You should do some more research then :P JK :)

There is a limit to how much light an MJ plant can use depending on how much CO2 is available (with the assumption that all other requirements are met, like nutrients, water, evironment, etc). Photosynthesis is catalyzed by light, but requires the raw materials, water and co2, to build carbohydrates (plant tissue). We can assume that water and nutrient requirements are always met, being cheap and abundant, but under extremely intense light (60w to 100w per sq.ft or HID lights too close), with atmospheric CO2 (especially in smaller SOG grow rooms) you hit a point where the amount of light hitting the plant's leaf surfaces exceeds the photosythetic capacity of the plant due to lack of CO2. This excess light ends up slowly destroying the chloroplasts which store chlorophyll in the leaves. This results in a slow "bleaching" out of the leaves, and essentially is a waste of light (power) and not healthy for the plant either. However, artificially increasing CO2 levels does allow the plant to utilize a lot more light than it otherwise could under atmospheric conditions, and this is why plants grow so fast when supplemented with CO2 under intense light (one without the other is useless). But even with CO2 enrichment, there is a limit to how much light the plant can use, albiet a much higher limit.

So to answer the original question:

is there such a thing as too much light. like 2600 w in a 4x6-6 area
That's over 100w/sq.ft. Yes, this is too much light, unless you are supplementing with CO2. The only other option is to raise your lights, which would provide you with nice even light coverage, but would be counter productive and inefficient.

People often make the argument that the Sun is way more powerful than HIDs and that if an MJ plant doesn't get too much light outside, how could it possibly get too much inside? Well, for starters, at it's very peak in midsummer at relative latitudes, the sun outputs around 10000 lumens per sq.ft. Then you have to factor in cloudy days (were that output drops to under 1000 lumens per sq.ft.), and the fact that the sun has to rise and set so you're only getting that 10000 lumens for a few hours during the afternoon in June (or December down under). So the assumption can be made that, on average, you might get 3000 lumens per sq.ft. over the whole growing season. Indoors you have none of those limitations. If you are providing 10000 lumens per sq.ft., you are doing this everyday for 18 or 12 (depending on the growth stage) hours a day with no clouds, etc. Sure, the quality of light may not be what the sun is, but it is still light. So, in a few words, yes you can have too much light indoors.
 

pickleman

Well-Known Member
the temps are 78-81 do u think i still need co2 with that much light.oh yeah i started w/1000 a little later went to 1600 then to 2000 and around week 6 1/2 went to 2600
 

Bob Smith

Well-Known Member
Only your plants can tell you if it's "too much" light (which is a very real concern, BTW, as anyone like me who has had plants bleached from excess light will tell you).

However, if your plants don't seem to mind, then no, it's not "too much", but it is pretty wasteful - there's going to be little to no noticeable difference with the addition of the 600, save that your energy bill is going to go up.

Trying to keep a room warm enough is a nice problem to have, however.
 
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