Round Custom DiY LED Challenge - Need Help!!

Say you wanted to build a round LED light fixture with a diameter of no more than 12'' and a width of no more than 2.5'', which has a PPFD of at least 900 umol/s/m2 at 18 inches from the center top of the canopy. The light should be able to perform equally for veg and flowering stages and also have the ability to be dimmed. I've researched almost about every thread in this forum and googled extensively and I'm still lost. I have an idea for a project I'm working on and I'm trying to accomplish this with the least expensive materials and parts available. I was thinking maybe using 2 HGL QB96 Elite v2 boards in series over some sort of round fixture but I can't seem to find the specs for that board in terms of PAR rating for each to see if it meets the demands and that option isn't really cheap either. I was also considering making everything from scratch which seems to be a more affordable approach using a custom board with a series of COB lights with the proper driver. In any case I'm somewhat lost as to what direction would be best and I was wondering if anyone had any input. Any advice or help or just a general point in the right direction would be very much appreciated. Thanks everyone.

have a great weekend,

AOG

ApexseasOG said:

Say you wanted to build a round LED light fixture with a diameter of no more than 12'' and a width of no more than 2.5'', which has a PPFD of at least 900 umol/s/m2 at 18 inches from the center top of the canopy. The light should be able to perform equally for veg and flowering stages and also have the ability to be dimmed. I've researched almost about every thread in this forum and googled extensively and I'm still lost. I have an idea for a project I'm working on and I'm trying to accomplish this with the least expensive materials and parts available. I was thinking maybe using 2 HGL QB96 Elite v2 boards in series over some sort of round fixture but I can't seem to find the specs for that board in terms of PAR rating for each to see if it meets the demands and that option isn't really cheap either. I was also considering making everything from scratch which seems to be a more affordable approach using a custom board with a series of COB lights with the proper driver. In any case I'm somewhat lost as to what direction would be best and I was wondering if anyone had any input. Any advice or help or just a general point in the right direction would be very much appreciated. Thanks everyone.

have a great weekend,

AOG

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Is your grow in a 5 gal bucket or what? Round lights don't give very good spread and DEFINITELY don't give even post on the corners of a square area.

Airwalker16 said:

Is your grow in a 5 gal bucket or what? Round lights don't give very good spread and DEFINITELY don't give even post on the corners of a square area.

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Grow would be in a 3 gal or 5 gal pot and the area is round, that's why I figured a round LED would be best suited to cover evenly down the cylindrical space.

ApexseasOG said:

Grow would be in a 3 gal or 5 gal pot and the area is round, that's why I figured a round LED would be best suited to cover evenly down the cylindrical space.

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Give more info and people will be more interested, willing, and able to give good feedback. Dimensions of the grow space is a primary factor, what's the diameter and height? Why round? Why 12" max diameter for the light?

1212ham said:

Give more info and people will be more interested, willing, and able to give good feedback. Dimensions of the grow space is a primary factor, what's the diameter and height? Why round? Why 12" max diameter for the light?

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You're absolutely right, I apologize; I'm sort of new to this forum thing.

Dimensions of the space is a plastic cylinder with a 20 in diameter and is 40 in tall. Total area is equivalent to roughly 2.17 sq ft. I decided to go with a round space because I have access to cheap 20x40 plastics trash containers which are straight with no angles and flat top and bottom. I'm thinking to retrofit these as a stealth grow space. The light has to be 12'' max diameter so I can fit the rest of the elements at the top of the container such as the carbon filter and other electrical components. I figured if I can get at least 28 inches in vertical grow space I can manage a good yield from a short auto-flower strain. I realize it's not the ideal space or set up but it's an experiment i'm hoping to do to see how well short auto strains can perform in that small space with all the other conditions at their best. I think autos are the future and this would be the way a lot of amateur growers would go once cannabis goes truly global; small, easy and fast. These could be put almost anywhere, wouldn't require a lot of power, and easy to maintain. These are the other add-ons I've been thinking to add to make the best our of the space and to maximize yield.

-Supplemental side lighting: 2 or 4 short t5 down the height of the container.
-Air ventilation: 1 inlet fan and 1 outlet fan; both with vents on opposite sides to shield any light leaks coming in and/or out of the container.
-Carbon Filter: I have a design I'm trying to build a circular filter which would be placed on the outer side of the led light around the edges of the top of the container; one side connected to the outlet fan and the other left open to collect the air inside the space. It's the same concept as the meshed pencil cups in different sizes with a panty hose and activated carbon; it's just in a circular shape.

No Worries. 30 watts/square foot is common with quality LED and one QB96 running around 65-75w would be more than enough, especially for autos, but I'd probably go with 2 ft strips on the sides and 1 ft on top. Here's Bridgelux EB GEN 3 in 340 and 560mm lengths. They are normally run around 7 watts/foot.


I'd ask over in the stealth/micro sub forum and check youtube for trash can/space bucket grows.

1212ham said:

No Worries. 30 watts/square foot is common with quality LED and one QB96 running around 65-75w would be more than enough, especially for autos, but I'd probably go with 2 ft strips on the sides and 1 ft on top. Here's Bridgelux EB GEN 3 in 340 and 560mm lengths. They are normally run around 7 watts/foot.

BXEB-L0340U-30E0750-C-C3 Bridgelux | Optoelectronics | DigiKey

Order today, ships today. BXEB-L0340U-30E0750-C-C3 – LED Lighting COBs Engines Modules LED Module series White, Warm Linear Light Strip from Bridgelux. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

BXEB-L0590U-30E1500-C-C3 Bridgelux | Optoelectronics | DigiKey

Order today, ships today. BXEB-L0590U-30E1500-C-C3 – LED Lighting COBs Engines Modules LED Module series White, Warm Linear Light Strip from Bridgelux. Pricing and Availability on millions of electronic components from Digi-Key Electronics.

www.digikey.com

https://www.bridgelux.com/sites/default/files/resource_media/DS171%20Bridgelux%20EB%20Series%20Slim%20Gen3%20Data%20Sheet%2020190620%20Rev%20A.PDF

I'd ask over in the stealth/micro sub forum and check youtube for trash can/space bucket grows.

Stealth / Micro / Cab Growing

Growing secretly, and in small spaces

www.rollitup.org

50gal. barrel stealth grow!

Just like the tittle says. Ill be growing inside of a 50 gallon barrel. I've got a few friends that wanna grow but don't have much room and are afraid to do more than a single plant. So I came up with an idea to use these barrels I have to many of. After cutting the door out the plastic warped...

www.rollitup.org

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Thanks for the reply! That's a great idea for the side lighting; they would also take up less space than a t5 fixture. I'm trying to figure out the driver for the QB96 and the 2 Slim gen3 which take 7.6w each. This is the only graphic I could find for the specs of the QB96; does this mean it takes 224w to run the light at max? So that would be 224w + 7.6w + 7.6w = 239.2w? Can I even run these 3 lights with the same driver?

I was suggesting strips instead of the QB96, not in addition to it. You have 3.14 sq. ft., so you only need 95w or so and less for autos. I'm thinking four 2ft. strips vertically and four 1ft. on top, but more strips gives better light distribution.

The chart just shows the relationship between volts and amps etc. HLG says "Max 4200mA with SSTX Heatsink and Thermal Pad"

Here's a grow with side lighting only.

1212ham said:

I was suggesting strips instead of the QB96, not in addition to it. You have 3.14 sq. ft., so you only need 95w or so and less for autos. I'm thinking four 2ft. strips vertically and four 1ft. on top, but more strips gives better light distribution.

The chart just shows the relationship between volts and amps etc. HLG says "Max 4200mA with SSTX Heatsink and Thermal Pad"

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Ohhhh..well that changes things quite a bit. In that case I would run a couple more on top to make it 6 x 1ft strips on top and 4 x 2ft strips on the sides; turns out to be 99.2w and at significantly less cost than with the QB96.

-4 x BXEB-L0590U-30E1500-C-C3 (slim Gen3) Vertical
total watts: 13.4 x 4= 53.60w at a cost of $38.16

-6 x BXEB-L0340U-30E0750-C-C3 (Slim Gen3) Top
total watts: 7.6 x 6= 45.6w at a cost of $43.20

grand total watts: 99.2w at a cost of $81.36

Do you think this setup will get me the PAR rating I was looking for or is that an overkill for a space like this?

I can't say what PAR would be but 100w would be plenty in that space. @captainmorgan Any thoughts, I'm thinking of those beautiful pics of your vertical grow, where do we find them?

With just 99.2w I could get away with a HLG-120H-54 driver correct? Max output for that driver is 124.2w.

No, that's a 54 volt driver. The voltages of the Gen 3 are 10.9v and 20.8v which complicates things since two of the short strips in series is 21.8v.

Both those strips are 700ma (1400 max) so I'm thinking of an HLG-120H-1050 with A or B dimming. The strips would be series wired for a total of about 141v.

I'd be interested to hear some other opinions, do it all with side lighting or run some on top also?

I'd go for just the one QB96 run at 100watts on a $30 XLG-100-H-A driver. Easy peasy.

PJ Diaz said:

I'd go for just the one QB96 run at 100watts on a $30 XLG-100-H-A driver. Easy peasy.

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How close could it be to the canopy? His grow space is only 40 inches tall.

1212ham said:

No, that's a 54 volt driver. The voltages of the Gen 3 are 10.9v and 20.8v which complicates things since two of the short strips in series is 21.8v.

Both those strips are 700ma (1400 max) so I'm thinking of an HLG-120H-1050 with A or B dimming. The strips would be series wired for a total of about 141v.

I'd be interested to hear some other opinions, do it all with side lighting or run some on top also?

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I see that now. I'm learning as I go; I really appreciate the feedback. I think I got a handle now on the difference between constant current and constant voltage drivers. All the info is daunting at first but once you start to understand it, it becomes easier to grasp rather quickly. A snippet from my research: "If you’re using a CV driver, then it needs to have the same output voltage as your LED’s voltage requirements. If you’re using multiple LEDs, add the voltage requirements together to determine the output voltage your driver needs. If you use a CC driver, make sure the output voltage exceeds the requirements of your LED lights.". I'm assuming having them run in a series allows you to have different voltages along the series but using the same current through them. In this case you need to add all the volts in the series to determine total volts needed from driver output.

PJ Diaz said:

I'd go for just the one QB96 run at 100watts on a $30 XLG-100-H-A driver. Easy peasy.

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That was my initial thought but then I also thought about the height restriction and how it would be best to utilize every inch available; to do so I have to make the lower side of the plant more productive in terms of yield and the only way to achieve that IMO would be from supplemental side lighting. The question would be if the supplemental lighting produces enough of a difference in yield to justify the cost to run them and if it would be more cost efficient just having the QB96 if yields are relatively the same with or without the side lights. My personal guess is that it would be worth it to add the side lighting but i'll let the pros share their thoughts.

Qb 96 @100w needs a lot of clearance to not bleach or burn. Op, have you. Considered using only sidelighting?

1212ham said:

How close could it be to the canopy? His grow space is only 40 inches tall.

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My bad, I missed that. Yeah prolly wouldn't give too much clearance.

Round led......?

Rocket Soul said:

Qb 96 @100w needs a lot of clearance to not bleach or burn. Op, have you. Considered using only sidelighting?

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Yes I have but it's tough to envision a maximum yield for this space without any sort of top level lighting. If the plant is bushy or too wide the top buds will not get any direct light thus affecting yield no? They might get a bit of light if the side lighting goes from the very top of the container down but I don't think it would be enough to maximize yield for the space IMO. It would be a fun experiment to try all these options out to see which is more cost effective in regards to yield per watt for such a small space.

ApexseasOG said:

Yes I have but it's tough to envision a maximum yield for this space without any sort of top level lighting. If the plant is bushy or too wide the top buds will not get any direct light thus affecting yield no? They might get a bit of light if the side lighting goes from the very top of the container down but I don't think it would be enough to maximize yield for the space IMO. It would be a fun experiment to try all these options out to see which is more cost effective in regards to yield per watt for such a small space.

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Id maybe put some 660 and 730 reds on the top but little else. This should give it the right verticality and youll be able to stretch the plant using 730nm far red