From HPS to LED to HPS to LED

[The Happy One]

Yes, the title is correct. The struggle is real for most of us, no doubt about it. And the struggle continues as we all strive to increase our yield and save a few bucks along the way, right?
Many years back, when the LED storm was first hitting, I jumped on board in a heartbeat and spent some hard cashola for some 1000 watt HPS replacements. After a few feeble attempts in flowering, it became apparent these "blurples" as I've come to call them simply didn't cut the mustard for flowering duties, apparent by their cute little buds, so they were retired into light duties such as clones and seedlings.
Fast forward to about a year ago when I was looking for a true HPS replacement, and was hearing all kinds of praises with these "new" LED's. So much so, I felt it might be worth a second look into. Maybe. It was then I decided to build a COB array. I still use this light, though it cant replace the two 600 watt HPS I had. This left me continuing the search.

I then looked into NextLight, because our local hydro shop had one. Pricey, no doubt, but it WAS a pretty "bright" LED.
At the time I was still running two 600 watt sealed and vented HPS lights in my sealed 6 plant medical grow.

Then...the same hydro shop put out another LED light claiming to replace a single ended 1000 watt HPS. From past experience my eyes were unable to focus until they pulled a full 360 degree of unbelief. This is when I was first introduced to Horticulture Lighting Group and their "Quantum" boards. This version of theirs was called the 550 and consisted of 4 separate boards screwed onto what looked like a piece of 1/4" plate aluminum with a driver secured to the backside. remember exclaiming how hot it ran and how bright the light was. I also remember thinking how much better cooling would be if the boards were mounted to a true heatsink with fins. I also felt they should have placed the driver at least on standoffs to keep those hot lights from dissipating heat into the driver. Otherwise, this light really was bright, and it wasn't a "blurple"...
I ended up purchasing a PAR meter JUST because of this light, as we were planning a bit larger grow and HVAC costs, electrical usage, ect. came into play.
I used the PAR meter at the local hydro store and I tested everything they had on display TO test. After testing the Nextgen and the HLG side by side, the HLG took 1st without batting an eye. I was pretty much blown away, truth told.
*On another note, after this HLG light pretty much running during the hydro shop's working hours for well over a year , the HLG was still plugging along, and doing so in an area I would call "not very well ventilated" so say the least. It had however began having a clear film to begin separating from the pcb board itself. Some airflow might have prevented this, however I KNOW cooling can be improved by moving the boards to a real heatsink. None of the LED's had quit working however.
I then began researching into why this LED seemed to outshine any other LED I've tested. This is when I was introduced to the Samsung LM-301b. This little chip is the reason the Quantum boards are such a rage today. Not the board per se, but the chipset that's on them.
I went with another brand, mainly due to the ability to move the boards around with the utmost ease with the frame they came with and each of the four boards includes their own heatsink.

The boards came with the hardware to connect them to a heatsink.

The frame is where this light goes beyond anything I have seen on the market today in the LM-301b dept. I think of it like an adult Erector set, because it allows placement of the boards just about anywhere you want for a perfect footprint.

The driver is located away from picking up heat from any of the 4 boards. It's an HLG 490 driver and they have been overclocked to 550 watts at the wall specifically

Though I haven't had a grow under these lights as of yet, I read the stories of many who have using the LM-301b's and I'm confident they will perform. The way we have them set up each plant receives their own LM-301b board, so each plant receives a good 137.5 watts each. Cant wait to see a harvest under these lights!

No matter what brand your looking into, if the light uses the Samsung LM-301b it's bound to perform outstanding.


Until something better comes along, I've yet to see a better cost/vs/performance solution. Peace!!!

 

[Nunyabiz]

I chose to do my LM301B in a strip light configuration because it gives a more even coverage and they run cooler.

These two easily replace a 1000w DE HPS
Burning 650w

 

[Schnookie]

I chose to do my LM301B in a strip light configuration because it gives a more even coverage and they run cooler.

These two easily replace a 1000w DE HPS
Burning 650w

Are these two distinct units? Do you have two drivers? Was this a DIY?

 

[Nunyabiz]

Are these two distinct units? Do you have two drivers? Was this a DIY?

Yes two separate lights, 325 watts each.
One driver each light.
Yes a DIY.
Around 2.8 umols/j efficiency.
Cost was about $390 each

I am running them dimmed down to 65 watts each right now for my seedlings and getting a very even PPFD of 290 umol/s/m2. at 15" from seedling.

 

[NeoScott]

Where did you get the heat sinks from @Nunyabiz I’m thinking of building a strip build. Are you using any uv or ir? You used the q series right? I was thinking of using the f series not as efficient but moar output. I was thinking of running 4 or 5, 4 foots at %50 for a 2 by 4 and adding in a little uv ir for flowering.

 

[bluter]

i like @Nunyabiz 's build
have some idle cobs i would like to pair with some of those strips.


i went over kill for the space

12 cob light rig.JPG

• bluter
• Sep 19, 2019
• 600 watt cob grow light

600 watt 12 cob citizen clu048 1212

old school cob.

 

[Stunned]

old school cob.

its funny how fast light tech changes when a really good setup like this cob array is now considered old school

 

[Nunyabiz]

Where did you get the heat sinks from @Nunyabiz I’m thinking of building a strip build. Are you using any uv or ir? You used the q series right? I was thinking of using the f series not as efficient but moar output. I was thinking of running 4 or 5, 4 foots at %50 for a 2 by 4 and adding in a little uv ir for flowering.

I bought both the heat sinks and strips from Pacific Light Concepts.
The strips are their own that they have made, they use nice aluminum boards for added durability and heat dissipation.
96 LM301B and 4 Cree XP-G3 photo-red diodes on each strip.
Can be run at 700mA 1400mA and 1900mA.
I run mine at 1400.
8 strips run at 325 watts at 100% and around 2.7 umols/j.
They dim down to 27 watts.
Run very cool.

 

[NeoScott]

I bought both the heat sinks and strips from Pacific Light Concepts.
The strips are their own that they have made, they use nice aluminum boards for added durability and heat dissipation.
96 LM301B and 4 Cree XP-G3 photo-red diodes on each strip.
Can be run at 700mA 1400mA and 1900mA.
I run mine at 1400.
8 strips run at 325 watts at 100% and around 2.7 umols/j.
They dim down to 27 watts.
Run very cool.

Thanks moar to read! Also what’s your lumens per fixture?

 

[Nunyabiz]

Thanks moar to read! Also what’s your lumens per fixture?

I've done just a few preliminary measurements and so far at 18" from canopy I get a reading of over 1300 PPFD
I can run these lights just 6" above canopy, at 6" at 100% I am at 114,000 LUX which comes out to about 1828 PPFD which is obviously WAY above being usable so needs to be dimmed down considerably.
I will most likely be running these dimmed by at least 30% to about 250 watts each so they will run very cool and over 1000 PPFD in center and 700+ on the outer edge and that's with just plain old white bathtub tiles for reflection, I assume a mylar or other highly reflective surface will bring the outer edges higher.

Running dimmed should also bump up my efficiency a bit.

 

[The Happy One]

I've done just a few preliminary measurements and so far at 18" from canopy I get a reading of over 1300 PPFD
I can run these lights just 6" above canopy, at 6" at 100% I am at 114,000 LUX which comes out to about 1828 PPFD which is obviously WAY above being usable so needs to be dimmed down considerably.
I will most likely be running these dimmed by at least 30% to about 250 watts each so they will run very cool and over 1000 PPFD in center and 700+ on the outer edge and that's with just plain old white bathtub tiles for reflection, I assume a mylar or other highly reflective surface will bring the outer edges higher.

Running dimmed should also bump up my efficiency a bit.

I fully agree with you my friend. We'll be dimming our boards for the first veg cycle, then try to only keep 1000-1200 PPFD over the canopy with no less than 700 PPFD around the edge perimeter, and that's with co2. Our preliminary testing has shown better than anticipated PAR reading around the outer canopy. We have Panda film surrounding all four walls so might have made more of a difference than I thought it would.
Frankly, I'm blown away with how far LED lighting has came since the days of me tossing a lot of hard earned cash on really pretty blurple 1000 watt HPS replacements... (my eyes are spinning in uncontrollable 360's). They do, however make black light posters looks cooler than they did in the 70's. Hey, I'm an optimist. What can I say?
Anyway, I cant see running them any harder than they need to be, and full bore is overkill. I had to turn the COBB array down in flower due to top burn and limited light height.

 

[NeoScott]

My iPad not working but I have a link on it to an article that suggest 15000 ppfd plus co2 around 28+c is your highest usable rate of light but you need to change your feed formula for that. It's a different game. You can't feed that plant like most people do you need boosters and stage specific nuits. Not just seedling/veg/flower but weekly changes including leaf analysts. Never ran that much light though. You should be able to use 1000 ppfd without needing co2.

 

[NeoScott]

I fully agree with you my friend. We'll be dimming our boards for the first veg cycle, then try to only keep 1000-1200 PPFD over the canopy with no less than 700 PPFD around the edge perimeter, and that's with co2. Our preliminary testing has shown better than anticipated PAR reading around the outer canopy. We have Panda film surrounding all four walls so might have made more of a difference than I thought it would.
Frankly, I'm blown away with how far LED lighting has came since the days of me tossing a lot of hard earned cash on really pretty blurple 1000 watt HPS replacements... (my eyes are spinning in uncontrollable 360's). They do, however make black light posters looks cooler than they did in the 70's. Hey, I'm an optimist. What can I say?
Anyway, I cant see running them any harder than they need to be, and full bore is overkill. I had to turn the COBB array down in flower due to top burn and limited light height.

I’m bothered by your cobs making so much heat.


Not that I’m some super grower(and it seems like you’ve got more experience then me) but if your turning your lights down during flowering your probably wasting light during the veg stage. 700 PPFD to 900(with co2) to my understanding as the plant just isn’t growing as much during veg as it does flowering. Your cobs shouldn’t make to much heat. I mean that’s the point of them right? Less electricity, better wattage to light(resulting in less heat) if your trying not to move your lights between the 18 12 and 6 maybe you don’t have enough cooling the plants. Your cooling system for light will only deal with radiation heat if you have a laser thermometer you can test the temperature of your leafs instead of the air. It really bothers me your cobs are burning your plant.

Your cobs should be making 60% light and 40% heat. Around that anyways.

 

[NeoScott]

Yeah sorry I was sober on that last post. You feed your plant 700 PPFD because you run a 18 hour cycle aiming for the 38 Dli (daily light intergrales) since the plant still needs 38 dli during flowering but your running a shorter day time you need to feed them more at once hence the increase to 900/15000 PPFD.

The point of changing the light time is to trick the plant into thinking it’s fall which has shorter days. If you live in the northern hemisphere your actually closer to the sun during the fall then the spring. Your just aimed more at the sun during the summer but further away.


Jesus Christ I’m stupid sober.