Bridgelux EB-series on a 2' x 4' SCROG

graying.geek

graying.geek

Well-Known Member
@Page { margin: 0.79in } p { margin-bottom: 0.1in; line-height: 120% }

Week 6 of 12/12. Predictably, after getting my wiring corrected (thanx, all!) I burned some of the pistils in the middle of the scrog where the light was too intense. Here’s a quick shot:
IMG_20170626_174729053.jpg
Not a big deal at this point. Only about half of the buds were affected and less than 50% of the pistils on the affected plants were toasted. Nevertheless, I raised the lights to about 10” off the canopy and dialed the drivers back to ~75% power. Still awfully bright in there, but hopefully that’ll make the girls happier. I assume part of the burning was due to the plants suddenly being inundated with so many more photons, but I suspect they’ll recover and continue to fatten up. We’ll see.

Anyone who uses these EB strips, any input on how high above your canopy?
 
BuddyColas

BuddyColas

Well-Known Member
graying.geek said:
@Page { margin: 0.79in } p { margin-bottom: 0.1in; line-height: 120% }

Week 6 of 12/12. Predictably, after getting my wiring corrected (thanx, all!) I burned some of the pistils in the middle of the scrog where the light was too intense. Here’s a quick shot:
View attachment 3967804
Not a big deal at this point. Only about half of the buds were affected and less than 50% of the pistils on the affected plants were toasted. Nevertheless, I raised the lights to about 10” off the canopy and dialed the drivers back to ~75% power. Still awfully bright in there, but hopefully that’ll make the girls happier. I assume part of the burning was due to the plants suddenly being inundated with so many more photons, but I suspect they’ll recover and continue to fatten up. We’ll see.

Anyone who uses these EB strips, any input on how high above your canopy?
Click to expand...
I say get a LUX meter. There is a good LUX to umols conversion thread in this section. That way you won't be guessing.:mrgreen:

Until then, now that you have dialed it down, how many watts are going to your EB panels?
 
graying.geek

graying.geek

Well-Known Member
When I noted the burn to buds and leaves primarily in the middle of my scrog after my lights were corrected, I loaded a lux app on my phone and recorded readings at the 4 corners and in 1 ft increments. Since Lumens will be variable by height above the canopy, I simplified the readings by dividing each reading by the lowest in the group. Here are the relative readings:

1.0 2.3 2.6 2.2
2.3 4.8 4.8 3.1
1.7 2.9 2.6 2.2

Obvious, even before I took the readings, was that the way my lights are arranged (0.75" spacing between strips), the middle of the scrog was getting significantly more photons than the corners or edges -- like DOUBLE. Applying a bit of reasoning to the design, I pulled out my light, replaced the 12" end cross members with 22" lengths of Al angle, and worked out the spacing between the strips to increase logarithmically to the middle thereby pushing more of the light out to the edges. If you look closely you can see that the spacing decreases as you move from the middle to the edges:

IMG_20170626_174713799.jpg

It worked nicely. Here are the new ratios:

1.2 2.0 1.7 1.5
1.2 1.5 1.5 1.2
1.0 1.2 1.1 1.0

Much better. This should give me a much more even photon distribution, and more even bud growth. Now I need to get the height above the plants optimized.
 
canadian1969

canadian1969

Well-Known Member
graying.geek said:
When I noted the burn to buds and leaves primarily in the middle of my scrog after my lights were corrected, I loaded a lux app on my phone and recorded readings at the 4 corners and in 1 ft increments. Since Lumens will be variable by height above the canopy, I simplified the readings by dividing each reading by the lowest in the group. Here are the relative readings:

1.0 2.3 2.6 2.2
2.3 4.8 4.8 3.1
1.7 2.9 2.6 2.2

Obvious, even before I took the readings, was that the way my lights are arranged (0.75" spacing between strips), the middle of the scrog was getting significantly more photons than the corners or edges -- like DOUBLE. Applying a bit of reasoning to the design, I pulled out my light, replaced the 12" end cross members with 22" lengths of Al angle, and worked out the spacing between the strips to increase logarithmically to the middle thereby pushing more of the light out to the edges. If you look closely you can see that the spacing decreases as you move from the middle to the edges:

View attachment 3967812

It worked nicely. Here are the new ratios:

1.2 2.0 1.7 1.5
1.2 1.5 1.5 1.2
1.0 1.2 1.1 1.0

Much better. This should give me a much more even photon distribution, and more even bud growth. Now I need to get the height above the plants optimized.
Click to expand...
thats great info man, thanks!!!
 
graying.geek

graying.geek

Well-Known Member
Danielson999 said:
If you harden your plants off properly, you can keep an EB strip or cobs within inches and have no problem. In 2 or 3 more days you can probably lower your light back down and keep it on 100% power.
Click to expand...
Thanx, Dan! This is what I was hoping for. Your experience validates my hypothesis.
 
graying.geek

graying.geek

Well-Known Member
BuddyColas said:
I say get a LUX meter. There is a good LUX to umols conversion thread in this section. That way you won't be guessing.:mrgreen:
Click to expand...
Thanx, Bud. I assume you're also using LEDs. What reading do you look for on your LUX meter?

: said:
Until then, now that you have dialed it down, how many watts are going to your EB panels?
Click to expand...
Haven't had a chance to check and my girls are down for the night, but now you have me curious. I'll check tomorrow.
 
graying.geek

graying.geek

Well-Known Member
Randomblame said:
50.000-60.000lx(~750-900μMol/s) in flower,
10.000-15.000lx(~150-220μMol/s) early vegging
25.000-30.000lx(~350-450μMol/s) late vegging

Conversion factor rounded up 0.015.
BTW, Cree CXB conversion factor for 3.500°k is 0.014152!
Click to expand...
Perfect! Thanx. You folks are making me lazy. :-)
 
BuddyColas

BuddyColas

Well-Known Member
graying.geek said:
Thanx, Bud. I assume you're also using LEDs. What reading do you look for on your LUX meter?



Haven't had a chance to check and my girls are down for the night, but now you have me curious. I'll check tomorrow.
Click to expand...
I am using the 3000/80 EB strips and I like to see 50000 LUX. Which converts out to about 720ish umols. I've had great results with 50K LUX at the top of the canopy.

https://www.rollitup.org/t/par-multiplier-thread.928907/

Every time I think about dropping some serious bucks on a good PAR meter, I just come back to the LUX meter which comes close...I'd say +/- 10% or so. Close enough for a hobby grower.

And I agree with Randomblame's figures.
 
graying.geek

graying.geek

Well-Known Member
BuddyColas said:
I say get a LUX meter. There is a good LUX to umols conversion thread in this section. That way you won't be guessing.:mrgreen:

Until then, now that you have dialed it down, how many watts are going to your EB panels?
Click to expand...
The numbers are not so odd. Running both drivers (2 x HLG-185H-1050A) at full power, here's the data on the input:

453w
113v
4A

Better. The wattage is obviously in line, but assuming everything is wired and running correctly, I still can't make sense of the amperage. IANAEE but seems like it should be higher, like more than double. Either there's something wrong, or the drivers are doing something I don't know about.
 
BuddyColas

BuddyColas

Well-Known Member
graying.geek said:
The numbers are not so odd. Running both drivers (2 x HLG-185H-1050A) at full power, here's the data on the input:

453w
113v
4A

Better. The wattage is obviously in line, but assuming everything is wired and running correctly, I still can't make sense of the amperage. IANAEE but seems like it should be higher, like more than double. Either there's something wrong, or the drivers are doing something I don't know about.
Click to expand...
If you are running those drivers wide open, then that is about 45w per strip. I'm saying you are getting in the vicinity of 95ppf per strip or 95 umols square foot or about 1000umols or so to your canopy if you run them close. OK, Randomblame...give us a second opinion!:mrgreen:
 
graying.geek

graying.geek

Well-Known Member
canadian1969 said:
Always interested in build specs, that would be great if you have time
Click to expand...
I regret that it took so long. Got wrapped up in my wiring issues.
eb-series_build_list.png
On my 2.4 grow areaI cut 1 angle-AL into 2 x 22" inverted cross members to the top of which I bolted each end of the 48" angle-AL lengths through my pre-drilled holes using 1/4" bolts, nuts and a lock washer. I calculated the spacing between the 8 angle-AL lengths -- and hence, between the strips -- on a logarithmically expanding scale from the sides to the middle to provide a MUCH more even light coverage.

2 of the bolts on each end were replaced with loop bolts for hanging/carrying. The double-sided tape was used to affix each strip to the bottom, flat surface of the 8 48" angle-AL lengths. Here's a shot of one end of the frame from the top. Sorry for the poor lighting. IMG_20170627_113131665.jpg

I used 14 AWG 2-wire between the drivers and the strips and 18 gauge single conductor to hop from strip to strip. Here's a diagram of the serial wiring pattern:
eb-series_build-e.png
Were I to order again, I'd get both the strips and drivers from Arrow. Prices are better and shipping is free. Digikey usually has better stock, but overall significantly cheaper from Arrow.

I also really recommend the 1 x 1 x 0.125 angle -Al from onlinemetals.com. It's sufficiently substantial that it makes a great frame and heatsink, and their prices are excellent compared to the likes of HomeDepot.
 
Serva

Serva

Well-Known Member
These strips are awesome! And also your light/grow looking good! It's nice to see someone else also did some exponential (what I did)/logarithmic spacing! I just followed my intuition, and it seems to work out great!
 
algebraist

algebraist

Well-Known Member
graying.geek said:
I also really recommend the 1 x 1 x 0.125 angle -Al from onlinemetals.com.
Click to expand...
Agreed about onlinemetal -- a great resource. When I ordered from them they gave me a great discount on shipping as a first time customer, and have emailed me other good offers since -- worth checking out.

Also, good call with the thermal tape! I recently finished my build and used bolts and thermal paste, which I will never do again -- the paste is tricky to work with, and although in theory it can give better conductivity, in practice it's hard to get the strips to lay flat enough for the paste to be in contact everywhere. And the bolts are a terrible idea -- it seems not all the holes are okay for mounting, and I shorted out a couple of strips by overtightening.
 
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