I was researching LED lights and I remember

skullcandy

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I understand that it would take 5004 watts of it how many feet up from the plant to get the effect of a cannabis plant that you get in the summer in half sun half shade where I live , I know it grows with a lot less but that’s a lot or I forget how to use a calculator.
Also how big would the grow area be for plants to sit through the whole grow and if you are good at math what would that wattage be reduced into a 4x4 tent ? What is the formula to solve that equation?
 
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oldfogey8

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You might be overthinking this…
If you plan on going LED, find one that is a ‘white light’ LED spec’d for a 4x4 footprint then go by the manufacturers recommendation for ‘fly height’. People on here seem to be happy with Spider Farmer and Mars Hydro. They both have lights for a 4x 4 space that I have been eyeing. Go with the best you can afford as lighting is very important.
 

WeedHopper

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This is my next purchase
I will use the 6400K for Vegg and 2700K for flower. Ive decided against the Leds . Ive grown some nice dank with HOT5s. And these are even better then the ones i had before.

GrowBright 4' 8 Lamp High Output T5 40,000 Lumens

The pictures below are from my old HOT5s.

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oldfogey8

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This is my next purchase
I will use the 6400K for Vegg and 2700K for flower. Ive decided against the Leds . Ive grown some nice dank with HOT5s. And these are even better then the ones i had before.

GrowBright 4' 8 Lamp High Output T5 40,000 Lumens

The pictures below are from my old HOT5s.

View attachment 314455 View attachment 314456 View attachment 314457
I have a 4 tube HTG HOT5 fixture(and a 2 tube too) that I have used the 10000k ‘finisher’ tubes in. I used them in veg and they work really well. It is weird because the website says they are red/yellow but the ones I have a ‘hurt your eyes’ blue. The bluish light gives you nice stocky vegged plants. They used to make a 10000k tube with UV A also which I mixed in with the 2700k bloom bulbs. Like you, I had very good results with HOT5’s.
 

skullcandy

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You are making something simple very hard. I have a 4 x 8 flower tent with two 600w hps lights. For a 4 x 4 one 600w would do fine.
I didn’t think about it much all I did was the calculations that I was given and I know it’s a big one but that would illuminate a big grow area an it would have enough lumes to grow just like it what out side in the shade during noon but sun in the morning an evening an outside plants grow pretty nice . What I was hoping was help finding the formula for reducing that power into a 4x4 tent I came up with 1400 -1800 watts of led hanging like a foot from 1-2 feet from the top of the tent but I am also curious what others calculate?
 

Growdude

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Watts dont mean much with LED lighting. Fixtures are measured by PPFD,Photosynthetic Photon Flux Density.
You will need to know PPFD per watt of the fixture your looking at, I use 2.8 PPFD per watt fixtures.

General rules used to be 50 watts per sq/ft or 5000 lumens per sq/ft
 

giggy

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as growdude said, hids, florescents and cfl's are by watts and leds are not. florescent lights are almost a thing of the past, we can't even get the cfl's anymore in the stores. you can still find them on line but that should tell you it is a dying breed. @WeedHopper they make led replacement tubes for your lights, check them out before you buy. i have changed a lot of the lights here at the shop to led tubes and the florescents can't touch them. we also pulled all our high bay metal halides out and went led, the mh's can't touch them either.
 

giggy

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oldfogey8

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WeedHopper

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as growdude said, hids, florescents and cfl's are by watts and leds are not. florescent lights are almost a thing of the past, we can't even get the cfl's anymore in the stores. you can still find them on line but that should tell you it is a dying breed. @WeedHopper they make led replacement tubes for your lights, check them out before you buy. i have changed a lot of the lights here at the shop to led tubes and the florescents can't touch them. we also pulled all our high bay metal halides out and went led, the mh's can't touch them either.
The HOT5 system I chose will work just fine for me. I have looked into LEDs that actually fit that HOT5 light system. Might mix them and see what happens.
My dank had pretty tight buds with HOT5s so I'm not to worried my harvest.
As for being a thing of the past I see them everywhere in the stores just like I use too.
I do agree LEDs are great lights especially for home use or shops. We have retrofitted most the government buildings with LEDs.
 

giggy

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The grow leds are a lot better then the lighting leds. The problem with buying a led grow light is they are under driven to make them last longer, but a well matched system will blow away a store bought light. I don't knock the t5's as they do a real good job, but they are on their way out because of the mercury that is used in them as well as the gas that is bad for us. When a CFL went bad you can smell it, which is bad.
 

WeedHopper

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oldfogey8

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I was looking at Led Grow tubes that are made to fit in the HOT5 system. Pretty cool.
I liked what I was reading on the Spider Famer SE3000.

I was looking at those yesterday. They look like they use 41 watts per tube vs 54 watts but the ones I saw for veg were 4600 lumens vs 5000. The flower version was 5200 lumens. They are more expensive but probably have a longer life(I think LEDs are touted as having 50000 hrs of lifetime vs 10000 for T5’s).
 

WeedHopper

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Might be cool to mix the 6400k HOT5s and 4600k LEDs.
You have a link to those LED tubes that fit the HOT5 light system you were looking at?
 
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