How Many LED's To Achieve 1,000 PPFD In 4x6

[Growtobig]

To me, i think you will need at least 50 strips to get around 1000 PPFD. Why don't you consider to buy a bar light like Gavita 1700e

[Danniel Shoemaker]

y'all are awesome ! everyone has moved my thoughts in some way and added something to my thinking.
I appreciate you very much. I love THCtalk.com <LOVE IT>

[CheapHomeGrown]

Umols PAR PPFD PPE Lumens. It's really confusing.

Have a look at a youtube channel called Migro he has some good stuff on there that will explain it far better than I can

My cheap TSW2000 has 684 leds for a 1x1 so it does not suprise me it's a large amount to be effective

The 35-50w is an estimate it does not mean you have to be at the top of the suggestion I can see why your looking to build the best system but I think your trying to make things to powerful the leds are only part of it the reflective ballast and positions and stuff is also important Migro can help you with that.

There are calculations that will help you convert all the different units to make more sense

The more I look into it the more confusing it become, you could have a rating of 1000 ppfd at 15cm, 2.9 but the center like 1400 and edges 300
You drop the light 40cm and all the canopy is between 400 and 700 but your ppfd is nearly half 600 ppfd, does than mean your lights round 2.1 at 40cm

It's very complicated, becareful what you read.

[GEORGE]

The picture below is is the correct strip. The above picture is the wrong one, sorry.

This one is;
** 52 LED's
** 22 inches long by 3/4 inch wide
** luminous flux = 1,460 (lm)
** 40 Volt, 14 Watt

So I was thinking that 20 of these strips might do it but that's
14W x 20 strips = 560 Watts

Does it make sense that I would need 85 of these strips?
Because 14W x 85 strips = 1,190 Watts
And the enclosure is 4 ft by 6 ft which is 24 square feet...
and 24 Square feet times 50watts is 1,200 desired watts...

right? I read on the world wide web of misinformation and opinions that instead of watts, it's better to consider PPFD but I only have the luminous flux (lm).
Can luminous flux be converted to PPFD...or at least an approximation of PPFD?

Attachment 406084

I'm in the process of learning A hard lesson. I have decovered that 50W per sqft is way over kill for my plant. Matter of fact, I almost kill it with Light burn. Trying to hit that high number with 950 to 1,000 PAR is way over kill. JMO

[GEORGE]

There is A guy over on google, that says that his plants grow better and bigger if he keeps his PAR in the 700 to 500 range. I am now starting to believe him. To achieve that range, 33W per sqft is fairly acturacty.

[Farmer Geddon]

I'm in the process of learning A hard lesson. I have decovered that 50W per sqft is way over kill for my plant. Matter of fact, I almost kill it with Light burn. Trying to hit that high number with 950 to 1,000 PAR is way over kill. JMO

50w psf is more than what many hps users give their plants. I used to give mine 37.5w psf. 600w hps covering 4'x4'. That dropped to 35w cmh psf, 1260w/36sft. In my cupboard, it's 45w psf cmh and that's plenty. The grow after this one will be 27w psf led, 190w/7sft.

[CheapHomeGrown]

50w psf is more than what many hps users give their plants. I used to give mine 37.5w psf. 600w hps covering 4'x4'. That dropped to 35w cmh psf, 1260w/36sft. In my cupboard, it's 45w psf cmh and that's plenty. The grow after this one will be 27w psf led, 190w/7sft.

The best I could get from a 600w se hps was 3ft x 4ft because of the design of the hood and the bulb, you get loads of light under the socket no light at the end of the bulb, (3ft) but the width would cover 4ft.
I have used a 600w se hps in a 2ft x 3ft wardrobe with great results,

[gardro]

When you have other limiting factors (feed, environment, medium etc) you have to limit ppfd to avoid issues but don't forget more ppfd is more bud. 700 will make good flower but 1000 will make a lot more. You can't get something for nothing mantra.

With premium led, what you lose in diminishing returns you have already offset in efficiency so no point running lower ppfd with led, gram per watt will reduce.

[CheapHomeGrown]

When you have other limiting factors (feed, environment, medium etc) you have to limit ppfd to avoid issues but don't forget more ppfd is more bud. 700 will make good flower but 1000 will make a lot more. You can't get something for nothing mantra.

With premium led, what you lose in diminishing returns you have already offset in efficiency so no point running lower ppfd with led, gram per watt will reduce.

So what about plants grown outside?
Plants will use the light they need, you may see no difference between 400 and 800 with an indica plant but will start to suffer under 1000 par for exsample.

[gardro]

So what about plants grown outside?
Plants will use the light they need, you may see no difference between 400 and 800 with an indica plant but will start to suffer under 1000 par for exsample.

Very true plants will use the light they need but also true they will yield more with more light.

Crops are proportional to DLI - farmers will tell you - no matter what the crop.

Indoor, we can increase their needs significantly in a carefully crafted environment.