DIY LED Strips

[jcmjrt]

I currently have Kessil H350s with fluorescent side lighting. I would like to go all LED and maybe let the T5s do some veg duty. The Kessils are red blue 90W LED magenta for flower. Seems like lots of folk are having some very nice grows with LED white light and it could fill any spectrum needs that the Kessils might not be (I haven't noted any deficiencies but that may be the fluorescents filling in). These would be sidelights so I was thinking that i would build them as a strip light.

The frame/heatsink would be 1 1/4" thick aluminum tubing used with a quality fan. The LEDs Cree XM-L - Warm, neutral and cool. I'm thinking 12 LEDs on a 30" length - that should give good side lighting coverage for the height of my plants (some sativa doms so can get tall). Pattern of WNCWWNCWWNCW evenly spaced along the strip. The leds are already mounted on mpcbs and I will mount them to the heatsink with thermal adhesive pads. The driver will be a dimmable inventronics 120 watt driving 2100mA...so each Cree should be using about 6.6+ watts each. If anything I was thinking about adding 2 warm white LEDs (one on each end) and having 14 LEDs...the driver is capable of it.

I rather like having the small modular lights as they seem to provide lots of flexibility. I'm thinking that in the future I could add deep red/far blue strips to add in for either veg or flower as appropriate...if I even ended up wanting to do that.

I'd love to hear your thoughts. I'm thinking about ordering my Christmas present to me and I'd like it to be nice.

 

[FranJan]

Actually I just can't see why people are so crazy about XMLs for growing when their spectral peaks are not that great for our uses. You'd get much better output if you went with mono lights IMHO. You gotta remember that white LEDs use metamerism/tri-stimulus values to create the illusion of white (natural) light. It's just a R+B with some G thrown in in this case and dedicated Red and Blue LEDs will give you more punch. You could probably veg with these lamps, but flowering is gonna be rough. Have you checked out Illumitex LEDs? That's my 2.

Good Luck!

 

[stardustsailor]

View attachment 2414535

Actually I just can't see why people are so crazy about XMLs for growing when their spectral peaks are not that great for our uses. You'd get much better output if you went with mono lights IMHO. You gotta remember that white LEDs use metamerism/tri-stimulus values to create the illusion of white (natural) light. It's just a R+B with some G thrown in in this case and dedicated Red and Blue LEDs will give you more punch. You could probably veg with these lamps, but flowering is gonna be rough. Have you checked out Illumitex LEDs? That's my 2.

Good Luck!

Uhhh..
Yeah!!!

That's the right way there....

Blue-Red...

Yeap!
All you need is bread and water....
...
Totally positive 100% sure....


Is the diarrhea inside the brain purple colored,I wonder ?...

 

[jcmjrt]

I've been surprised by how some folks are anti-Kessil (suggested retail price I understand..which I didn't pay) and say they can't grow well. I'm having great luck with them. The veg was great and now I'm about a month into flower and my plants look happy and the flowers are just stacking up. But I do realize that I have fluorescent side lights and am wondering if the quality of my grow is related to filling in the spectrum? It's hard to know as some folks will bad mouth anything but I can say that I do know what a healthy happy plant looks like and mine are thrilled. I've also seen several grows on here with white LEDs and they are having some good luck.

I'm not sure how I'd have difficulty flowering since the side light LED will be dominant warm white and the Kessils are providing red and blue only for flower. Would a different combo of whites be better?

Hey, I'm not an expert at all...just an organic grower who can solder and I want LEDs that are on wavelength and producing what they are supposed to. I'm pretty sure top bin Cree meets that and then it's up to me to match the driver and keep the heat under control so that the LEDs can do their proper thing...something many commercial LED makers don't really do in order to cut corners and save money. I'm going for a quality product that I can live with for a while. Well, that's my hope....

Any other thoughts out there?

 

[Chronikool]

White LED's (warm and cool white) will work well....i think that the neutral whites are unnecessary. Their spectrum seems to fall in the middle of bum fuck no-where...!

 

[stardustsailor]

White LED's (warm and cool white) will work well....i think that the neutral whites are unnecessary. Their spectrum seems to fall in the middle of bum fuck no-where...!

NW might be a good idea to be used (in small quantity ) along with B+R actinic combos..
It might...

 

[gachogavacho]

Hey JC did you every post pictures of your build?

 

[MrFlux]

White LED's (warm and cool white) will work well....i think that the neutral whites are unnecessary. Their spectrum seems to fall in the middle of bum fuck no-where...!

Well spectrum-wise there is not much difference between mixing warm and cool white or just using a single neutral white.

 

[stardustsailor]

Well spectrum-wise there is not much difference between mixing warm and cool white or just using a single neutral white.

Allow me to disagree with that statement ....

In most CW & WW leds ,the same type of blue die is used as an excitation source,most of the times ...
For example a blue chip of ~450-455 nm ...
Their different spectrum is due to different phosphors(and quantity/load) used...

In the most cases ,a NW led has same phosphor blend-load-mix as a CW led ...
The 'trick' usualy used ,in order to make their output light more 'neutral' is by using a different blue excitation chip ,of shorter wl...
(by this 'trick' ,shorter blue wls ,appear ' dimmer ' to human vision,thus the output light becomes 'warmer' than the one from CW leds=Neutral White )
For example a blue chip of 440-445 nm ...

So ,roughly speaking :

WW = 455 die + amber/red phosphor
CW = 455 die + yellow phosphor
NW =445 die +yellow phosphor
Thus :

CW+WW = 455 dies +yellow phosphor + amber/red phosphor

While ...

NW+WW = 445nm +455 nm +yellow phosphor + amber/red phosphor

In second case ,the blue range is significally 'broader' (and somewhat lower in power terms )than in first case ..

Furthermore I've tried both ...

NW+WW combos are better suited for growing ,than CW+WW combos ...

Solely, a NW led ,in order to resemble a CW+WW combination,it should be of high CRI .. (and of lower efficiency,than the ones with mid CRI )
( If not, it lacks amber/red wls found in a WW led .It's just like a CW,with shorter blue wls ...)


My humble opinion is that CW leds are superb for automotive ,industrial and other applications ..
In growing plants ,they offer nothing ,but better "green color rendering " ...
It's like having blue leds with a hint of green ....

I think it's more preferable to use either few blue leds with some green ones
(Heliospectra-style)
or plenty of NW leds ,instead...
(Astir style )

Now ....
Enjoy her ...
(While thinking about it .. )
[video=youtube;i3GuJ9GlhAs]https://www.youtube.com/watch?v=i3GuJ9GlhAs[/video]

 

[MrFlux]

SDS, how about playing a game. I post a spectrum and you tell whether it's a blend of warm and cold or if it's a neutral...

 

[Positivity]

I tend to look at the proof in the pudding rather than numbers and ideas

the xmls have something a lot of other leds don't....light intensity. Lots of light. It became obvious they needed a little help in the red department during flowering. But once some seperate reds were added that are probably more efficient than a white could hope to be....magic. Big, icky, sticky, smelly flowers. Gonna take some proof to sway me now...lol

very unscientific, I know, but in the end it works really really good.

 

[Positivity]

Just wanted to add I think your light setup would be awesome like that

if I could redo my panel I'd make it more modular like your idea. I use the inventronics driver and so far smooth running, love the built in dimming function. Also at 2.1a, seems a good current before they start getting really hot. I'd just go all ww with supplemental reds and maybe even one royal blue and violet somewhere in the pattern.

Two drivers per bar with dimming, can't see that not working really well.