Homemade Far Red Fixture?

Tag: @dbrn32 the lighting expert.

I want to add IR/Far Red to my grow, and HLG’s bulb is discontinued. It seems easy enough to build my own … Steve’s LEDs has far red LED components on sale, but I’m not sure how to pick a driver (or which driver).

Can anyone tell me what driver (preferably from Steve’s) would work with 1, 2, 4 of the Luxeon 3w far red leds? (Or how I should figure that out myself?)

I figure I’ll get a aluminum square bar and mount it all to that to heat sink the LEDs…



Grab a screen shot of whatever led’s ur looking at. I tried googling and they have alot going on lol. Thatll defo help the light doc


Forever Green Indoors has a great far red led bar for like $150 right now.
It’s a solid piece of equipment and covers my 2x4 space perfectly.


I hope this is ok to post (Steve’s LEDs doesn’t compete with ILGM):

The LEDs are {sorry coulnt pretty it up}

Their Meanwell drivers are at www dot stevesleds dot com/MeanWell-Drivers_c_98.html, there are other choices but I’d like to get good drivers… Feel free to recommend something else.

Yes, but I was thinking more in the $30-40 range (all-in).

Edited for links


You have heatsink material for them or no? Asking to determine operating current. They are listed at 700ma, I think you would need at least a decent piece of aluminum flat stock to mount them to.

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I can certainly help you build this. If you’re looking for easy without spending a lot, this guy will run on $8 wall power supply. Plug and play


Yea, maybe that’s a easier way to go.


I don’t really know your background or what you have laying around. I have literally everything else needed to build this out. If you don’t, could get nickel and dimed into spending $50 easy. You’ll have $10ish plus shipping into leds. Probably another $15 in driver. Heatsink, wire, thermal paste/epoxy, stuff like that will all vary a little depending on what you get. Assuming you already have soldering iron, solder, and flux too. The rapid led is under $40 with power supply, and no work other than plug it in.


That’s fair. I have everything I’d need already except the LEDs, driver(s), and heatsink(s). My soldering is ugly but works fine.

If I wanted to build a strip of 3 or 4 LEDs (9-12 watts), and was using the LEDs listed above, which driver(s) should I choose from Steve’s home->parts->drivers?


Works great for a 2x2 also. I have one in the 2x2 well had I switched it with a hlg 50w but might go back as the rapid fit in there much nicer


You’re going to decide how many watts they pull by driver choice. The quoted spec of led posted above is 700ma max current and forward voltage of 2.3v at 700ma. I would choose something lower than max current to run them at, 500ma or maybe even 350ma. At 500ma forward voltage may drop a little too, so you would be looking at about 1 watt per led. Even at 700ma they are about 1.6 watts per led.

So should I look for a driver to run 3-4 leds or 10-12 watts worth?

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Mmmm. 5’ by 5’? I’d say 12w…

You could do meanwell plm 12-500 and something like 8-9 of leds you have listed above wired in series. Would put you about 10 watts or so on input.

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@dbrn32 The far red puck you posted, how much space will a single one cover? And when do you add far red into the flower cycle? From the beginning?

Can you point me to some explanation on how that’s calculated?

I’m exploring other LED options (like the far red Cree XP-E, which 2.25v, 1000ma)?

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E*I=P. In long form that is volts * amps=watts.

So the Xpe at 1000ma would be a 2.25 watt led. Again generally speaking most won’t run any leds at full current.

I use cree xpg3 on mine and run them at 500ma.

So, to run 3 LEDs that are Vf=2.9v @ 700mA (e.g.), that’d be 3*(2.9*.7w)=6.09w … so I’d be looking (in this example) for a LED driver with … >7 or 8w and … um … what are the other parameters? Don’t you have to pick one that supplies 2.9v? Confusing. Seems like there are more things to look for…

Depends on how leds are connected. You’re going to have a hard time finding ac to dc driver that will be that small. Then again running with exactly 2.9vdc. In most case would consider these 3v and wire 4 in series to create a 12v circuit. Then looking for drivers to run this small of circuit is going leave limited options. Then type of driver you get will determine how circuit behaves. Cv driver will prioritize voltage and allow leds to pull current they want up to maximum output of driver. Cc driver will prioritize current.

Understanding how to size what you need is only small portion of what needs to happen here. You have to be able find the stuff to make it work. If you’re gonna use 2.9v leds then you need a cv driver with 2.9v output and support desired current of the total circuit. OR you need cc driver that has voltage range acceptable to the total circuit voltage of your leds.

Yes but no, watt and amp are different and not interchangeable. 2.9 volts x .7 amps = 2.03 watts. 3x = 6.09 watts. This assumes you have driver that will do this, which i don’t know if you’ll find.

I’m trying to understand … I’ve had physics, I know that W = V * A…

The PLM-12-500 has 12W rated power and 15-24V constant current. If I want to use Vf=2.9v @ 700ma LEDs, how do I calculate whether that supply will work for the LEDs? There’s something I’m missing here.