I switched from High Pressure Sodium to COBs. My experience

TerrapinBlazin

Well-Known Member
If its just for veg then get a 4 pack of hlg QB132s and a hlg 120h-c1050a driver and wire in series. Should give 140 ish watts.

That will give you better light spread over a 3x3 than a single board which would be intense in the centre and weak on the outsides.
They also do not need heatsinks and you can dim
Thanks. I have a feeling I’ll be blowing my Christmas bonus on lights. Is there any benefit to wiring them parallel? I mean besides the obvious benefit of the other boards/chips still run if one fails
 

sandman83

Well-Known Member
Hi Al,
I agree with the mixed spectra idea. Did MH and HPS together back in the day. Now use cmh and led. About 600w of each.
For a 3x3 using 30watts/sf you would want way more then 100w. My math shows 270w minimum.
JD

Quick Q, for sizing QB's vs HPS, does the 50w per ft rule still apply or is 30w per ft of LED (from the wall) the equivalent?
 

TerrapinBlazin

Well-Known Member
Cobkits only has the 288 for sale. Would two of those be good? And an HLG 120h 48a driver? That’s what I’m finding that’s available for a good price.
 

JohnDee

Well-Known Member
Quick Q, for sizing QB's vs HPS, does the 50w per ft rule still apply or is 30w per ft of LED (from the wall) the equivalent?
It's my understanding that with the greater efficiency of leds...the watts per square foot can be lower. 30 is just the number I've seen guys quote. Seems reasonable. 50 w/sf or more....is what guys do with hps. You could go higher on the leds and dial it back for even greater efficiency.
JD
 

coreywebster

Well-Known Member
Quick Q, for sizing QB's vs HPS, does the 50w per ft rule still apply or is 30w per ft of LED (from the wall) the equivalent?
Yeah John is right.
30-35 is standard for LED now we use strips and boards. Lots of folks used 50 with cobs for a direct swap and increase in yield , but the trend seems to be lower for boards ect.
Some run as low as 23w per square foot, one thing to note, if you have strips ran soft and grow scrog or sog style you can get those strips real low and close and get the same par at canopy using less power and because they are nice and spread and even your not losing out on uniformity much.
 

diggs99

Well-Known Member
Yeah John is right.
30-35 is standard for LED now we use strips and boards. Lots of folks used 50 with cobs for a direct swap and increase in yield , but the trend seems to be lower for boards ect.
Some run as low as 23w per square foot, one thing to note, if you have strips ran soft and grow scrog or sog style you can get those strips real low and close and get the same par at canopy using less power and because they are nice and spread and even your not losing out on uniformity much.
Yep, this for sure

My strips can basically be placed on top of my plants without any concern at all to the plant. Only concern would be to the leds themselves.

Last run i kept my lights approx 2-3" above tops after stretch was over, putting out 70-80,000k lux across the canopy. As you said tho, mine are being ran hella soft. I adjust by dimmer to get the numbers i want.
 

coreywebster

Well-Known Member
Yep, this for sure

My strips can basically be placed on top of my plants without any concern at all to the plant. Only concern would be to the leds themselves.

Last run i kept my lights approx 2-3" above tops after stretch was over, putting out 70-80,000k lux across the canopy. As you said tho, mine are being ran hella soft. I adjust by dimmer to get the numbers i want.
Yours are the cutter cree j series arnt they diggs?
 

Aeroknow

Well-Known Member
It's my understanding that with the greater efficiency of leds...the watts per square foot can be lower. 30 is just the number I've seen guys quote. Seems reasonable. 50 w/sf or more....is what guys do with hps. You could go higher on the leds and dial it back for even greater efficiency.
JD
We are usually at 40w/sqft with DE Hps. Or, around 4’ and 6’ centers with 1000w DE’s. I was at 4’-6” and 6’ centers on my last grow which is 37w/ft and I routinely pulled 3+lb’s per light.
Only reason I posted this is because no one ever mentions the double ended when comparing led to “hps” in these threads.
 

TerrapinBlazin

Well-Known Member
Okay we’ll see how this works. I decided to order shit off amazon for the free shipping. Got a driver and a board kit with heatsink, hangers, and wiring for about $110 all in.

Driver is a meanwell hlg 100h 46a and the board is a Samsung lm 310b

hope those are compatible. Let me know quick so I can cancel the order if they aren’t. My guess is that these will work fine for my 3x3 veg/clone tent and they’ll be a lot more efficient than the $35 blurple grow light and LED security spotlights I have in there :/
 
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sandman83

Well-Known Member
Yeah John is right.
30-35 is standard for LED now we use strips and boards. Lots of folks used 50 with cobs for a direct swap and increase in yield , but the trend seems to be lower for boards ect.
Some run as low as 23w per square foot, one thing to note, if you have strips ran soft and grow scrog or sog style you can get those strips real low and close and get the same par at canopy using less power and because they are nice and spread and even your not losing out on uniformity much.
Thanks! I've got 2 of the sf2000 over a 2x4 space each, just wanted to make sure I was supplying enough light before I considered flipping the lights on this room.
 

TerrapinBlazin

Well-Known Member
Canceled the 100h 46a and swapped it for a 120h 36a. I just snapped that the 100 means voltage and I’ve gotta have 120 volts. The second number seems like it’s for amps, but that doesn’t make sense if you use those numbers in the wattage formula.
 

nevergoodenuf

Well-Known Member
Nobody has mentioned room temps??? This is one of the most important changes with LEDs. The temps should be in the low 80* due to almost no IR. 3000K/90cri was the most similar to the growth of the DE. Almost identical to the DE in stretch. If you need the stretch control in the first 2 weeks, you could add a few watts of 6500k for a couple hours mid day. Could also be added at finish.
 

coreywebster

Well-Known Member
Canceled the 100h 46a and swapped it for a 120h 36a. I just snapped that the 100 means voltage and I’ve gotta have 120 volts. The second number seems like it’s for amps, but that doesn’t make sense if you use those numbers in the wattage formula.

No, The 120 is the wattage of the driver, the second number (36) is the voltage it provides the letter is the type of dimming.
Unless there is a C before the second number like 120h-c2100 , which means its constant current.

The constant voltage driver needs to be wired in parallel.
The constant current driver is wired in series and provides every board/strip the listed current.

The constant voltage driver puts out a total current which is divided by the amount of boards/strips in parallel connection.

With the 120h-36a it will match the QB132 boards you were looking at.



Edit, you better link the exact boards on amazon because they may not be what I was talking about in the first place and its very important you match the driver to the boards , especially with constant voltage
 
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TerrapinBlazin

Well-Known Member
No, The 120 is the wattage of the driver, the second number (36) is the voltage it provides the letter is the type of dimming.
Unless there is a C before the second number like 120h-c2100 , which means its constant current.

The constant voltage driver needs to be wired in parallel.
The constant current driver is wired in series and provides every board/strip the listed current.

The constant voltage driver puts out a total current which is divided by the amount of boards/strips in parallel connection.

With the 120h-36a it will match the QB132 boards you were looking at.



Edit, you better link the exact boards on amazon because they may not be what I was talking about in the first place and its very important you match the driver to the boards , especially with constant voltage
Driver — I couldn’t find the exact one the board manufacturer recommended, so I got the 36a instead of 56a

MEAN WELL LED Driver Single Output Switching Power Supply 120 Watt 48V @ 2.5A A Model, 120 Watt - HLG-120H-48A https://www.amazon.com/dp/B00DEDANWU/ref=cm_sw_r_cp_api_i_A2S6DbHWKAMTQ

Board

Atreum Lighting 288.2 LED Grow Light Board Kit, Horticulture Full Spectrum Grow Light Panel, Samsung LM301B with Heatsink, Hanging Rope and Solid Copper Cables https://www.amazon.com/dp/B07VSZ2PNS/ref=cm_sw_r_cp_api_i_q3S6DbFC2X5JZ

Will this work? It isn’t too late to cancel. Also is this even worth building? Be honest. I’m trying to do something cool for my tent on the cheap that will be a learning experience but I want this to be a really good veg light too. Is 3000k good for veg?
 
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TerrapinBlazin

Well-Known Member
I thought it looked like a nice little setup. I mean a board, heatsink, wire, and hangers for ~$70 and it looks nice. I couldn’t find the exact driver they recommended but I think it’s close enough. I don’t see needing more than one of those boards so I didn’t see any reason to get a more expensive driver.
 

pthobson

Well-Known Member
I don’t know if anyone has mentioned it yet but I know with LED you actually want your ambient temp to be a few degrees hotter than you would aim for with HPS. Can be a little tricky at first because obviously LEDs run cooler
 
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