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How much light is TOO MUCH?

G

Guest

hello everybody,

I think my latest upgrade may have pushed me over the edge....

I have read that plants need 25 watts per sq.ft. I think most of us safely exceed this requirement. I recently increased my wattage to 800W for an 8-sq.ft., that's 100W per sq.ft.

At what point (W/sq.ft.) will I need to supplement CO2 to utilize the extra light? How much light (W/sq.ft.) can be absorbed by a plant without CO2 supplementation?

I may be using the wrong measurement, please let me know. Thanks and take it easy.

- No Worries

oh yeah, its 800W of pure and beautiful CMH lighting, if that makes a difference.
And here's a little something to look at for your trouble... SSH 6 weeks flowering:
 
Y

yamaha_1fan

not sure if light and C02 have any relation. Just never heard it mentioned. Heat and C02 have a relation, that I know.

I think over 100w psqf is enough. Anything over that is probably wasted

I think for MJ the requirement is 50-60w psqf
 
sativo

sativo

Member
NoWorries said:
Click to expand...

Wow, I love the colors in that pic, and the plant is so alive with nice perky leaves, did you grow her? What a beauty.
To answer your question, I say the more light you have the more bud you'll get, so, start stuffing plants in there :D
 
yohomz

yohomz

Member
Co2 and light definitely work together! You don't absolutely need supplemental Co2 but you will see a BIG difference if you do use it. If you do supplement Co2, make sure you only use it when the light is ON. If you have high temps in your room, Co2 will help your plants cope with that too. Like I said above, you don't need supplemental Co2, but definitely keep your temps in check if you're not using it (and also if you are).


BTW, very nice bud shot! SSH is one of my all time faves.
 
G

Guest

my assumption was based upon limiting factors. if a reaction is A + B = C and you have more A than B, then B is wasted. I'm just hoping that CO2 isnt a "limiting factor" and light is not in excess. thoughts?

thanks for all of the replies. The SSH in the picture was grown by me and that grow is still underway (see signature). Take it easy.

- no worries
 
Last edited:
G

Guest

alright, I'll consider this debate settled. thanks for the advice. I can definitely see what you're saying about the sun, good point. thanks again. 800W here I come!

- no worries
 
G

Guest

Hey Man!!

They are right. No such thing as too much light. However, you can have too much heat. Make sure you can keep temps down and your plants will LOVE you!

:sasmokin:
pedro
 
T

twojoints

Member
ive been running two 400 watters in a 3'x3'x6' space... its very easy to pull 6 dried oz's each crop... i should be getting more i think though...
 
G

Guest

twojoints said:
ive been running two 400 watters in a 3'x3'x6' space... its very easy to pull 6 dried oz's each crop... i should be getting more i think though...
Click to expand...

You really should be getting more IMO. My Hydrohut mini is39"x39"x78"...just slightly bigger than your space...and I got over 5oz from just 2 haze hybrids, not known for big yields last grow....and I easily had room for one more plant of the same size in there. I'm certain I could get 8+oz from a good Indica. My first grow was an Indica grow, and I got 7.5oz not counting what I lost from a broken branch and what I smoked early. All on just one 400 Watter.

You need to look at your setup. Something isn't right if all you can get is 6 oz.

pedro
:sasmokin:
 
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Mr Celsius

Mr Celsius

I am patient with stupidity but not with those who
Veteran
Co2 is most effective when using 75w per sq ft or above, past 100w per sq ft its basically pointless.

Look, a plant can only grow as fast as its limiting factor. If running a constant 1500ppm co2 and 100w per sq ft, its probably going to be your medium/temps/humidity/nutrients that is limiting you.

If you have 1500ppm co2, 100w per sq ft, 70% RH, 82 degree F, aeroponic system with 68 degree F water with optimal nutrients at the right time then you would see the most potential and yield out of your plants. Its only going to give you a little more yield and isn't worth the hassle.
 
mudvaynefan

mudvaynefan

Member





Heat was not an issue, I noticed really slow growth, so I moved them and used cfl, picked up just fine.

100w hps, just too much light for the young seedlings.

Again, heat was not an issue here, they did fine till month later over fed and killed most. Not all, kept clone.
 
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