Putting it to the test

[OneHitDone]

Trust me if I had more amps I could load on my cricut I would gladly bump it up to 1k. But 750 watts is what I can run safe and allow me to sleep at night. So that's what it has to be

Just know that not many will give much credit to your outcome - Cheap hps lamp (DIMMED), wing reflector etc.
Top tier led vs bottom of the barrel hps

 

[Gorillaglue4u]

Just know that not many will give much credit to your outcome - Cheap hps lamp (DIMMED), wing reflector etc.
Top tier led vs bottom of the barrel hps

I'm not proving to anyone I'm proving to my self which is better in my situation. I used to run lumatek 1000s with hortilux bulbs but have not noticed no difference in brightness compared to cheaper bulbs so don't feel the need to buy all the expensive stuff anymore. If I can lower my light bill and get a better yield then it is enough justification for my self. Like I said I'm not a good grower I hope no one takes my advice. But if someone is going to buy all the expensive hoods and ballasts and bulbs then they will spend just as much on a led that will run more efficient for the same results and don't have to spend 90 bucks on a hortilux bulb every other grow.

 

[Gorillaglue4u]

Just for the record I'm doing this just because I couldn't veg my plants any longer or they would have been a pain in the ass if they got any bigger. I did this just to post now and again about the differences I see growing under the led and the hps.
Everyone's room is set up different. We all run different equipment. Some in a garage some in a house some in a basement. This grow is for my situation and only mine.

AGAIN EVERYONE READING IM A SHITTY GROWER AND DONT TAKE ANY THING I POST SERIOUS.

 

[skoomd]

Just know that not many will give much credit to your outcome - Cheap hps lamp (DIMMED), wing reflector etc.
Top tier led vs bottom of the barrel hps

A lot of new diy LED growers dont get much credit for their outcomes either lol, pulling down almost 2 gram per watt yields their first or second grows and then the HPS crowd goes and talks about how the LEDs can't equal twice the watts of HPS. I dont think ive ever seen a new grower using HPS pull 1 gram per watt their first or second grow. So it's proven that 1w of the LEDs can indeed equal 2w of HPS, it's just about technique And if a new grower can do it, then of course an experienced one should be able to as well

 

[Viceman666]

A lot of new diy LED growers dont get much credit for their outcomes either lol, pulling down almost 2 gram per watt yields their first or second grows and then the HPS crowd goes and talks about how the LEDs can't equal twice the watts of HPS. I dont think ive ever seen a new grower using HPS pull 1 gram per watt their first or second grow. So it's proven that 1w of the LEDs can indeed equal 2w of HPS, it's just about technique And if a new grower can do it, then of course an experienced one should be able to as well

There has been so much conversation about hps vs LED.. while at work today and thinking about my next build, i just ended up going back to basics and it just makes a little more sense now.

1000w HPS = 110 000 lumens = 110lm/w

For a LED to be exactly 2 for 1 you would need 220lm/w to get the same lumens output.

If you run your LED at 170lm/w then you do 110k / 170 = 647W

This seems very simple but yet I think its one of the best math you can to compare the two. It doesnt account for all factors (spectrum, some will say "penetration", size, spread, etc).. but the numbers are there. LED will provide better uniformity because you can spread them so much more over your canopy and the hps is 360 degrees so you loose more off the reflection but all in all simple math for the win!

 

[skoomd]

There has been so much conversation about hps vs LED.. while at work today and thinking about my next build, i just ended up going back to basics and it just makes a little more sense now.

1000w HPS = 110 000 lumens = 110lm/w

For a LED to be exactly 2 for 1 you would need 220lm/w to get the same lumens output.

If you run your LED at 170lm/w then you do 110k / 170 = 647W

This seems very simple but yet I think its one of the best math you can to compare the two. It doesnt account for all factors (spectrum, some will say "penetration", size, spread, etc).. but the numbers are there. LED will provide better uniformity because you can spread them so much more over your canopy and the hps is 360 degrees so you loose more off the reflection but all in all simple math for the win!

The problem with that is lumens dont grow plants. We want to look at umol/j using PAR. Lumens = light for humans, PAR = light for plants. PAR stands for photosynthetically active radiation.

HPS is on avg. 1.3 umol/j

Todays LEDs are on avg. 2.3umol/j

So if you had a 1000w HPS, you would have 1300PPF of output (1000 * 1.3). PPF is Photosynthetic photon flux, aka how many raw photons in the PAR range that are emitted from the light.

And lets use 500w of LED strips, you would have 1150 PPF of output (500 * 2.3).

Now, this is a curveball I know, but PAR doesnt tell the whole story. The spectrum of the light must be taken into consideration when comparing PAR between 2 different lights. If those LEDs were all 6000k, the PPF would be the same but obviously 6000k wont yield as much as the 2100k HPS at almost the same raw output.

But we usually use 3000-3500k for LEDs, which packs in considerably more red, far red, and green wavelengths in the spectra than the 2100k HPS does (and also blue to keep plants growing naturally and not stretched). HPS is mostly yellow, with red and far red being the rest of the main spectra.

So even if the PPF output is identical, the LEDs contain more of the wavelengths that drive the most photosynthesis. So theory says the 3000k LEDs should perform better at the same PPF as the HPS. HPS does contain heavy levels of IR, which mix with the far red to make the emerson effect which is important too. But you can add IR to the LEDs of course.

***********************************************

So hopefully that explains how people are achieving the results of an HPS, while only using half the watts. The raw numbers tell us the 1000w HPS should beat the 500w of LED strips since the PPF is higher. But the spectra of the LEDs drive more photosynthesis than the HPS spectra, so it can close that raw PPF output gap.

And that's not to mention the fact LEDs have been proven over and over (and over and over...) to increase cannabinoid and terpene content across the board over HPS. Which for extractors who make hash, is a HUUUUUGE deal.

 

[InTheValley]

well HPS has a great Red value also, which ultimately is what really gives the plants girth and growth.

thats what ive come to the conclusion on.

add that and the photon throw power, You got a great growing light.

 

[skoomd]

well HPS has a great Red value also, which ultimately is what really gives the plants girth and growth.

thats what ive come to the conclusion on.

add that and the photon throw power, You got a great growing light.

Yea it does, but white 3000k ish LEDs actually have more overall reds, far reds, and green which in bright white light is nearly as good as red for photosynhesis. Green also penetrates the canopy very well. And you cant forget the blues the LEDs pack in there, which have been shown to increase trichome production dramatically and of course keep plants from stretching like they would under say an HPS...

I think many HPS growers miss this point and just look at raw data alone and then they come to the conclusion that you cant grow with LED using half the watts to get the same results. It is WELL known that the reason HPS works so well is simply because it's a cannon that just blasts yellow and red light, which is why they yield so well. But when white LEDs are here and they put out more reds, more greens, more blues, and less IR heat emmision and UV (both of which arent nearly as useful as anything in the PAR 380-720nm range).while also being as much as twice as efficient, it's clear as day to me. And I have seen plenty of grows on both sides results, including my own.

Here is a standard HPS SPD graph

And various LED color temp SPD graphs

 

[OneHitDone]

Yea it does, but white 3000k ish LEDs actually have more overall reds, far reds, and green which in bright white light is nearly as good as red for photosynhesis. Green also penetrates the canopy very well. And you cant forget the blues the LEDs pack in there, which have been shown to increase trichome production dramatically and of course keep plants from stretching like they would under say an HPS...

I think many HPS growers miss this point and just look at raw data alone and then they come to the conclusion that you cant grow with LED using half the watts to get the same results. It is WELL known that the reason HPS works so well is simply because it's a cannon that just blasts yellow and red light, which is why they yield so well. But when white LEDs are here and they put out more reds, more greens, more blues, and less IR heat emmision and UV (both of which arent nearly as useful as anything in the PAR 380-720nm range).while also being as much as twice as efficient, it's clear as day to me. And I have seen plenty of grows on both sides results, including my own.

Here is a standard HPS SPD graph

And various LED color temp SPD graphs

Your 660:740 ratio is whack and making bonsai plants.
What about all that violet to the left? You are trying to increase terps?

 

[skoomd]

Your 660:740 ratio is whack and making bonsai plants.
What about all that violet to the left? You are trying to increase terps?

I think I am totally missing what you're saying here lol.

What 660:740 ratio, and what violet lol? Bonsai plants?