-boring 'ol 230w 154lm/w led strip build

wietefras said:

Actually we look at umol as you stated before. HPS spectrum is no more efficient and in fact the lumen to umol conversion is greater for HPS (so you end up with less umol per lumen).

Either way, HPS produces 1150umol/s for 600W ie 1.9umol/s/w. The 154lm/W strips come out at 2.1umol/s/W. So indeed that's only a small advantage for the led. Sill, at this price point that's already fine.

However the real losses with HPS are further down the line. An HPS bulb produces 1.9umol/s/W, but then you lose 20% of the light on the reflector. So then you are left with 1.5umol/s/W leaving the reflector on its way to the plants..

Then come the wall losses. A 600W HPS needs to be at about 20" to 24" above the plants. At lets say 1% per inch of height (for a 4'x4' tent woth decent reflective walls) makes it a 20% loss at least. Which means you end up with 1.2umol/s/W by the time the light reaches the plants.

Led strips can be at 4" and lose only 4%. So from that 2.1umol/s/W you end up with 2.0umol/s/W by the time it reaches the plants. Although in fairness, a lot of the growers here seem to hang their lights at 18" or something so they needlessly incur extra losses.

Still even if we leave those wall losses out, 1.5umol/s/W leaving the HPS reflector vs 2.1umol/s leaving the led strips is still quite a decent advantage for the leds.

Click to expand...

wietefras said:

Actually we look at umol as you stated before. HPS spectrum is no more efficient and in fact the lumen to umol conversion is greater for HPS (so you end up with less umol per lumen).

Either way, HPS produces 1150umol/s for 600W ie 1.9umol/s/w. The 154lm/W strips come out at 2.1umol/s/W. So indeed that's only a small advantage for the led. Sill, at this price point that's already fine.

However the real losses with HPS are further down the line. An HPS bulb produces 1.9umol/s/W, but then you lose 20% of the light on the reflector. So then you are left with 1.5umol/s/W leaving the reflector on its way to the plants..

Then come the wall losses. A 600W HPS needs to be at about 20" to 24" above the plants. At lets say 1% per inch of height (for a 4'x4' tent woth decent reflective walls) makes it a 20% loss at least. Which means you end up with 1.2umol/s/W by the time the light reaches the plants.

Led strips can be at 4" and lose only 4%. So from that 2.1umol/s/W you end up with 2.0umol/s/W by the time it reaches the plants. Although in fairness, a lot of the growers here seem to hang their lights at 18" or something so they needlessly incur extra losses.

Still even if we leave those wall losses out, 1.5umol/s/W leaving the HPS reflector vs 2.1umol/s leaving the led strips is still quite a decent advantage for the leds.

Click to expand...

Yodaweed said:

Well stated, however you did not account for the additional IR that HPS has, LEDs lack that in the spectrum that's why i said the HPS spectrum is more desirable.

Click to expand...

Also LEDs have poor intensity since their light source is more spread out so you need to keep them close to the plants

Click to expand...

Bottom line is a 600w hps would crush 600w of these LED strips

Click to expand...

Until a true side by side is done with equal wattage all the LED numbers and bloviating is nothing more than conjecture, HPS is tried and true.

Click to expand...

Yodaweed said:

Well stated, however you did not account for the additional IR that HPS has, LEDs lack that in the spectrum that's why i said the HPS spectrum is more desirable. Also LEDs have poor intensity since their light source is more spread out so you need to keep them close to the plants , i'd imagine these strips would need to be no further than 12 inches away and probably around 8 inches would be best so you will have very poor coverage and very poor distance to light.

Bottom line is a 600w hps would crush 600w of these LED strips, they have a very poor light distribution they cannot be far at all from canopy, these are for micro grows.

In the real world all those bloated numbers you are saying do not pan out, LEDs have too much blue in them , that's why they output such high PAR but do not convert to flowering plants as well as a quality HPS. White LEDs are blue LEDs with a spray coating on them, the spectrum is not desirable for flowering, they could make a great veg light but they also lack UV which is essential to vegging and flowering plants.

Until a true side by side is done with equal wattage all the LED numbers and bloviating is nothing more than conjecture, HPS is tried and true. All the grows i see with these strips are pretty disappointing, could be the growers or it could be the lights, i have not been impressed from what i have seen one iota.

Click to expand...

wietefras said:

That's debatable. Only one test grow showed marginal advantage for HPS in that respect. Without keeping inmind that you can raise the temperature of the room and achieve the same.

That's nonsense. you CAN keep them close to the plants which is an advantage. ie 20% less wall losses potentially.

That's complete and utter nonsense. Time and time we have shown here that it's the other way around. And that's from when people were using 134lm/W CXA leds.

Read this whole LED subsection of the forum. Not one DIY led gets beaten by HPS. What rock have you been living under?

Click to expand...

nmibud said:

Have you actually grown with these strips?I do, and they work just fine!Your bias is in ignorance of the facts.These strips are far cheaper than hps,and produce very little heat.Instead of insulting something you know nothing about just move on with your old world tech.

Click to expand...

Yodaweed said:

I reserve my judgement until I do a side by side or another quality grower does. You could be right about DIY being better but there's no quality grow comparisons so everything seems to be hypothetical.

Click to expand...

Yodaweed said:

You LED fanboys can bash me all you want, but it does not make your right.

Click to expand...

wietefras said:

We are bashing you because you keep ignoring blatantly obvious facts. I guess that's how it goes nowadays in the US, but in the real world facts still matter. People have been yielding more per watt with leds for years now.

Click to expand...

wietefras said:

What on earth do you think people have been doing here since 2014? Tons of grow reports that put HPS grows to shame.

Even with "low" efficiency leds from years ago. I used to get around 1.5g/W on average even with my first a 2.0umol/s/W DIY light. While with Gavita Pro HPS I would get on average 1.1g/W. With similar 550 to 600g/m2.

Click to expand...

Yodaweed said:

You know nothing, heat is produced by watts used, 100w of LED strips = 100w of hps , first law of thermodynamics.

You are the ignorant one, ignorant of the facts and laws of physics.

You LED fanboys can bash me all you want, but it does not make your right.

Click to expand...

Yodaweed said:

Nice, you got a side by side done or nah?
If not it's all just opinion, you might have become a better grower or used larger yielding strains. Too many factors unless you perform an actual side by side comparison using the same of everything besides the lights.

Click to expand...

PSUAGRO. said:

WTF is that supposed to mean?..... Breaking out the broad brush again I see

Click to expand...

wietefras said:

Well it's true.

Click to expand...

wietefras said:

Well it's true.

Click to expand...

Humple said:

It's true the world over, friend. Every nation has its foolish and its wise.

Click to expand...

Making sweeping statements about a country in which you do not live and about people you do not know?

Click to expand...