You might need more light for flowering. 50 real watts per square foot of tent is the general rule. Very high efficiency LEDs might get by with a bit less. The main sign of low light is small airy buds and low production.
have a 1500wat and a 1000 wat high intensity 3 chip LED lights in 16 square feet. so i got 125 wat per square foot…and i thought the whole thing about triggering flowering was LESS light and longer dark periods???
The “1500 watt claim” is just marketing hype. That draws 320 watts from the wall, so it’s a 320 watt light. So you probably only have 42 watts per square foot. But that should be enough with LEDs.
To flower you need at least 12 hour dark periods that are really really dark. But during the light periods, more light equals more bud.
i’m willing to say 1500 watt claim on an LED is really more like 1000wat HPS light…but with HPS HALF the energy is waisted as heat that you have to pipe out of the tent if you don’t want to fry your plants! then you have to get rid of that heat form the house. for ever wat of energ energy used to create heat it takes 2 wats of AC energy to cool/get rid of the heat.
so great as HPS lights are a 1000 wat HPS produces 500 wats of light and wastes 1500 wats in unwanted heat and cooling.
my LED actually EATS 350 wats, but produces 300 wats of real spectrum focused light and maybe 50 wats of waisted heat, so 150 wats of heat and cooling.
it’s a larger outlay initially but simplifies everything else after, and way safer, and no overload issues with multiple tents to. the results so far are good, but harvest time will tell the true story, i may be compleatly wrong…but for my first grow so far so good as the optimist said as he fell off the roof of a 50 story building.
i will keep updating with pics as i reach mile stone points, and of course harvest weights and bud pics fingers crossed and god willing!!
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thanks that’s good to know i was going to take out one of the LED lights during flowing…given more light during the shorter light phase means more bud…it’s staying firmly where it is!! lol
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i have two main LED lights a 1000w pulls 260w and a 1500w pulls 320W
i also purchased two cheap led panels…$26 a pop…probably best we don’t talk about those!! lol
it does have red and blue LED’s !!! that’s where the good news starts and ENDS …I suspect my galaxy S5 put out twice as much light as each of thouse cheep panels…it was an experiment to see how good the “inexpensive” passive non fan cooled panels were…well the answer is pretty shitty LOL…but i have them as side panels anyway…can’t hurt! lol
Hate to burst your bubble, but even the very best, most efficient LEDs (COBs) put out about half their watts as heat. My 400 watt HPS lamp put out 133 lumens per watt and the very best LED COBs they make put out about 180 lumens per watt if you run them at 1/3 power or less, and then the LED drivers put out another 5% of the power as heat if you get really good ones. Bad drivers can burn up 20% as heat.
But it really does not matter in terms of heat production: Cannabis is only about 6% efficient in terms of turning photons into sugar. So at least 94% of your power ends up as heat, one way or another. And that’s only the light that hits a leaf. Light that misses leaves becomes 100% heat.
LEDs just have a big heat sink, so their temperature should never get very high, but don’t confuse temperature with energy. HPS lamps have no heat sink, so they get very hot. But if you exhaust the same amount of hot air from either, the air will be close the same temperature. I actually have a 400 watt HPS lamp in one grow chamber and 400 real watts of COBs in another. Their exhaust streams are both just moderately warm, about 90 F.
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all interesting information. my grow tent is reflective so let’s hope a lot of the LED light that does not directly hit a leaf, get reflected and hits other areas, underneath maybe? and help th3 grow. I find the fact that weed only uses 6% of light energy fascinating, as it’s probably one of the fastest growing plans other than cudsu or bambo…and we now have solar panels at 13% so to out do nature is quiet something. i guess the plants only take what they need for health growth!
i did find that removing the glass from the LED panel reduced heat still more. see my video![Reducing heat from LED light by removing glass panel]
I concur @1BigFella. And a watt for watt a 600HID is more effective then 1k. And just because a light claims to replace a 1kHID meaning hps/mh. And says its a 1500watt led ddoesnt mean it will. Even the cheap amazon leds will grow good meds if its a light to grow cannabis. Brands like mars/hydro ,hollandstar, dimigogo and king make lights with cannabis in mind.
The dimigogo 1k actually pulls 230-250watts, 12band full spec uv , triple chip, double fan and can be daisy chained. All of those are under 200$ range. Kind, meihzi, blackdog some next step up.
If you use a HID light and a cool tub the same fan that u use with your charcole filter can cool the light and pull exhaust air threw filter to be cleaned before venting. In winter vent in your house for added heat.
OH good! i did good then i picked the Dimogo triple chip LED. i have a 1000 wat a 1500 watt (i like the fact it is physically larger and throws light over more area) and my third Dimogo 1500w arrived yesterday from amazon, along with my second light tent i ordered.
as you say at the moment the heat is a bonus during winter. i have plans to cut a round hole in a closet cealing and run the ducting through it and put the air scrubber in the loft for summer. will also be a good bit quieter.
My wife loves the heat! I have a vent to the outside for summer, but in winter I close that off and point the duct into the house. She’s not really a smoker, but likes the scent. We are out in the country so we have to use propane for heat: Electric heat is pretty competitive.
like most weomen my wife also likes it toasty. but ironically the scent of the plants gives her a wicked head ache which is interesting because eating edibles (the whole reason i have started grow my own) gives her total relief of her migraines she normally gets twice or more a week! nature is amazing the way it has a cure for every ailment and poison it produces!
That’s wh6 i purchased the carbon filter with the blower motor to create a proper air scrubber! no smell at all and not a sign of a head ache caused by the smell since…in fact i would go as far as to say the air scrubber has improved the air quality of the whole house (our home is somewhat open plan)
ok So. this is 3 months in and touch wood all looking promising
i also thought i’d post the soil i’m using and the fertilizers for magnesium nitrogen etc that seem to not be causing any harm. adding the blood meal and magnesium directly onto the soil then covering with a little more soil and watering. no burn so far. only using every 3rd watering
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Ya, it definitely doesn’t work like that. The power consumed from wall is the total of light produced and efficiency losses. So you start with 320 watts and remove driver efficiency figure 88% to be generous that’s almost 40 watts. Figure another 10 watts of cooling fans minimum. Due to the price of the fixture vs amount of diodes, I’ll bet they’re less than 35% efficient. So of the 270 watts remaining, that’s like 95 par watts vs 215 heat watts plus the other 10 watts for cooling.
That’s the difference between a 1200 watt light that costs $120, and a 600 watt light that costs $800.
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Some big girls you have there @surfrescue. Good job!
so my second tent was ready for harvest, out of 3 blue dream and one gold leaf i got 2.5 lbs of blue dream wet, and half a pound of gold leaf wet. so 3lb for the 4x4 tent. i’m very happy with that. I know i can improve on that with better pruning and SCROG growing…but that’s a 50% yield increase over my first tent. i’m getting better at this, and given i’m using LED and over crowding my tents…i’m please with the results! with time and experience will come better yield. but that’s more than enough than we need to make the Canabis butter for my wife to make the edibles to treat her pain from fibromyalgia and daily Migrain. ONLY canabis helps both and reduces pain by 80% way better than the oxicodine the Dr prescribed!
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also i was finding i was having coughing fits after pruning my ladies, bit of repurchase found that others develope breathing problems when spending a lot of time trimming plants. so i decided some breathing mask would be worth a go! $45 from amazon, gets you this baby. comfortable to wear easy to breath cuts out the smell, and not one single caugh after spending 4 hours with the ladies pruning watering and harvesting and purring up to dry!
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