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Need Help With LED's

Hasnain

Active Member
Hello Everyone,

Thanks for reading this!

I've got a small space of 2x2 ft = 4 sq.ft, and I have a doubt regarding the lighting.

I've read in multiple threads that 30-40watts per sq.ft should be adequate, and i'd love it if some of you could confirm that?

for example if i'm considering 30watts per sq.ft, then i'd need 120 watts for 4 sq.feet.

so thats exactly what i'm doing, i've got 4 full-spectrum 30watt lights which i'm gonna use.

here's the lights i've purchased:-
61FzYm2OHUL_SL1001_.jpg


i'd really appreciate it if someone could let me know if these lights are good enough?

it's my first time with LED's
.


Thank You!!!!
 

Scientific

New Member
It's probably not the answer you want, but as long as your working with white (rather than blurple) light, you can buy a digital lux meter at Amazon for $16 that will tell you just what you want to know. Shoot for sunny summer day light levels of 80,000 to 100,000 lux for good yields. Less than that will keep the plant alive, but if you want lots of good quality flowers, go for 80,000+ lux.
 

Skullman420

Well-Known Member
Can keep a plant alive i bet and perhaps even give you 5-10 grams per lamp
 

Hasnain

Active Member
It's probably not the answer you want, but as long as your working with white (rather than blurple) light, you can buy a digital lux meter at Amazon for $16 that will tell you just what you want to know. Shoot for sunny summer day light levels of 80,000 to 100,000 lux for good yields. Less than that will keep the plant alive, but if you want lots of good quality flowers, go for 80,000+ lux.

Thanks buddy,

These are the "blurple" ones.

80,000-10,000 lumens sounds like a lot... Rule of thumb is about 7000 lumens per plant right? Plus.. I heard that when dealing with LED lights, lumens are not as important coz the quality of light is what matters?

Would love to hear from u again, cheers. [emoji1303]
 

Hasnain

Active Member
Can keep a plant alive i bet and perhaps even give you 5-10 grams per lamp

Alright, that's not bad for a trial I guess [emoji4] what if I'm using the Sea Of Green Method? Will this setup be good for about 4-6 plants in a 2x2 sqft area?
 

gbauto

Active Member
I'm pretty sure that the 30W/sq ft is ACTUAL power consumption. So for that space you should shoot for at least 120W of power used-not what the lamp's equivalent incandescent power rating. I think that the lamp you pictured is about 10W/lamp of actual power consumption.
 

Hasnain

Active Member
I'm pretty sure that the 30W/sq ft is ACTUAL power consumption. So for that space you should shoot for at least 120W of power used-not what the lamp's equivalent incandescent power rating. I think that the lamp you pictured is about 10W/lamp of actual power consumption.

That's a 30w bulb actual power consumption for sure, and I'm using 4 of them. So that's 120w in total. Is that ok?
 

Scientific

New Member
Thanks buddy,

These are the “blurple” ones.

80,000-10,000 lumens sounds like a lot... Rule of thumb is about 7000 lumens per plant right? Plus.. I heard that when dealing with LED lights, lumens are not as important coz the quality of light is what matters?]

Ah, blurple. Not so easy to measure.

The rule for white light is 80,000 to 100,000 lux, not lumens. One lux is one lumen spread out over 1 square meter, so if you have a 5000 lumen light but it's close to the plant so it's only spread over 1/10 of a square lumen, you get ten times as many lux, so 50,000.

But we're talking blurple here, so unless you have a $200 light meter, all bets are off. (I can't wait for that price to come down, and I'm sure it will eventually.)

So then you're back to the experience of people with LED grow lamps and you get figures like 30 watts per square foot, but of course ya gotta be careful about the watts on the box (the max power rating of the LEDs) versus the actual power consumed from the outlet, usually about 1/2 that, but it seem really variable. I have a little blurple that says 12 watts and uses 9 watts, but I saw a "1000 watt" the actually only used about 150 (!?!). Clearly, going with name brands like Mars Hydro might be best for that reason. You also have the advantage of a gazillon Mars Hydro users out there you can compare notes with.

So I guess your first order of business is to figure out how much power your lights are actually using...

If in doubt, MORE LIGHT!!! :)
 

Scientific

New Member
Those are fine for house plants or clones possibly veg in a mini/micro setup but your not going to get a lot of output from them. They will suffice but that's all. Not hating my setup is 80% blurples just being realistic.

If they're nominally 30 W and actually 15, then with 4 you're getting 60 actual watts, and that's not very much.

Just by way of very rough comparison, this Dwarf Low Flyer was about 16" across and had a mix of 10 CFL and LED light bulbs for about maybe 200 true watts or so. It did very well, but that's actual 200 watts on one little dwarf plant.

Cannabis wants LOTS OF LIGHT! There is a BIG difference between enough light for it to grow and enough light for it to really produce!

2017-05-04_Day_45_1100_002.JPG
 

Hasnain

Active Member
Ah, blurple. Not so easy to measure.

The rule for white light is 80,000 to 100,000 lux, not lumens. One lux is one lumen spread out over 1 square meter, so if you have a 5000 lumen light but it's close to the plant so it's only spread over 1/10 of a square lumen, you get ten times as many lux, so 50,000.

But we're talking blurple here, so unless you have a $200 light meter, all bets are off. (I can't wait for that price to come down, and I'm sure it will eventually.)

So then you're back to the experience of people with LED grow lamps and you get figures like 30 watts per square foot, but of course ya gotta be careful about the watts on the box (the max power rating of the LEDs) versus the actual power consumed from the outlet, usually about 1/2 that, but it seem really variable. I have a little blurple that says 12 watts and uses 9 watts, but I saw a "1000 watt" the actually only used about 150 (!?!). Clearly, going with name brands like Mars Hydro might be best for that reason. You also have the advantage of a gazillon Mars Hydro users out there you can compare notes with.

So I guess your first order of business is to figure out how much power your lights are actually using...

If in doubt, MORE LIGHT!!! :)

Thanks for your input my friend, I'll just give these lights a try, it's just a trial after all. Let's see how it goes, I'll post pics in a week or so.

I live in Chennai which is a city in Southern India, where the weed is sold by shady dealers who lace the weed with RAT POISON and even OPIUM sometimes... so even if I don't get a great yield right now, it's fine.. coz a small yield of good clean stuff is better than this poisonous shit I get here!

Right now my aim is to see if this works, and later I'll concentrate on maximising my yield.

Thanks again man.
 

Hasnain

Active Member
Ah, blurple. Not so easy to measure.

The rule for white light is 80,000 to 100,000 lux, not lumens. One lux is one lumen spread out over 1 square meter, so if you have a 5000 lumen light but it's close to the plant so it's only spread over 1/10 of a square lumen, you get ten times as many lux, so 50,000.

But we're talking blurple here, so unless you have a $200 light meter, all bets are off. (I can't wait for that price to come down, and I'm sure it will eventually.)

So then you're back to the experience of people with LED grow lamps and you get figures like 30 watts per square foot, but of course ya gotta be careful about the watts on the box (the max power rating of the LEDs) versus the actual power consumed from the outlet, usually about 1/2 that, but it seem really variable. I have a little blurple that says 12 watts and uses 9 watts, but I saw a "1000 watt" the actually only used about 150 (!?!). Clearly, going with name brands like Mars Hydro might be best for that reason. You also have the advantage of a gazillon Mars Hydro users out there you can compare notes with.

So I guess your first order of business is to figure out how much power your lights are actually using...

If in doubt, MORE LIGHT!!! :)

Also, what if I'm using the Sea Of Green Method? Will this work better if I'm keeping my plants short??
 

Scientific

New Member
I have always wanted to see India. Maybe someday...
Let's see, rat poison or opium? Opium please!
Sea of green: I think that regardless of which method of training you chose, you're still going to need a certain amount of light for good results.
Because of the fact that I mentioned earlier that fewer lumens spread over a smaller area gives more lux, your seedlings won't need as much light–in fact one lamp will do for a seedling. But as they get larger the light gets spread out and so you'll need more. At flowering you need even more to get dense buds and lots of THC.
You can tell when you don't have enough because the plant will get spindly.
Since you are going to try limited light:
  • I suggest growing just one plant.
  • If it is a photoperiod plant, switch to flowering early to keep the plant small.
  • If you have a choice of seeds, get a dwarf strain.
  • If you can get an auto flower strain, give the plant light 24 hours a day to compensate.
  • Sunlight can help a lot too if you have a window or private balcony or garden.


Good luck and have fun!
 

Hasnain

Active Member
I have always wanted to see India. Maybe someday...
Let's see, rat poison or opium? Opium please!
Sea of green: I think that regardless of which method of training you chose, you're still going to need a certain amount of light for good results.
Because of the fact that I mentioned earlier that fewer lumens spread over a smaller area gives more lux, your seedlings won't need as much light–in fact one lamp will do for a seedling. But as they get larger the light gets spread out and so you'll need more. At flowering you need even more to get dense buds and lots of THC.
You can tell when you don't have enough because the plant will get spindly.
Since you are going to try limited light:
  • I suggest growing just one plant.
  • If it is a photoperiod plant, switch to flowering early to keep the plant small.
  • If you have a choice of seeds, get a dwarf strain.
  • If you can get an auto flower strain, give the plant light 24 hours a day to compensate.
  • Sunlight can help a lot too if you have a window or private balcony or garden.


Good luck and have fun!

Thanks man, I'll keep everything u said in mind. [emoji1303]
 

Skullman420

Well-Known Member
I gave a 25 watt bulb like that to a friend. He managed to grow and flower a tiny pure power plant under it. Sure, he did not get much medicine. Perhaps 10 grams max. But for him watching this tiny plant grow was therapy in itself.
 
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