Blurple Cobs?? Anyone?

gwheels

Well-Known Member
Get a quantum board or cobs or HPS/MH or CMH. They all really work and really work better than a cheapo.

And if you have some dough to spend get a pro made one. :D If not get the parts list and build one (or growers choice will do it for a very minor charge).
 

Boatguy

Well-Known Member
Thanks for the advice, but i wasnt linking to a light. Those are individual cobs. Unfortunately the datasheet doesnt show efficiency, just spectrum etc.
I do see quite a few people here supplementing their cob or strip spectrum with far reds and blues, and this seemed like a simpler addition considering its a single cob.
 

Rahz

Well-Known Member
Thanks for the advice, but i wasnt linking to a light. Those are individual cobs. Unfortunately the datasheet doesnt show efficiency, just spectrum etc.
I do see quite a few people here supplementing their cob or strip spectrum with far reds and blues, and this seemed like a simpler addition considering its a single cob.
Not sure which sample @nfhiggs did the math on, but you can find the voltage ratings here: https://www.lumileds.com/uploads/696/DS195-pdf

This is basically what we've been keeping an eye out for years. Would/will be interesting to see how they compare umol to umol above plants.
 

CobKits

Well-Known Member
ive got samples of citi and luminus ones here, i just havent had any time to do sphere work on them. and i dont have enough of each to throw plants under and draw any useful conclusions.

i think its fair to say that you need less PAR with a targeted spectrum. otherwise wed all be using blue and green monos
 

Boatguy

Well-Known Member
Wish i had seen these a week ago. I picked up some cree cmt-2890's and a couple of 12" Horticultural strips from thomas research last week. May have to make a mini light with those strips and give one of those cobs a spot in the middle.
 

Rahz

Well-Known Member
ive got samples of citi and luminus ones here, i just havent had any time to do sphere work on them. and i dont have enough of each to throw plants under and draw any useful conclusions.

i think its fair to say that you need less PAR with a targeted spectrum. otherwise wed all be using blue and green monos
But how much less? 2%, 5% 10%?

I suspect it will be less than 5% over white, but I am eager to see some results when they come around.

Who will be our test bunny?
 

CobKits

Well-Known Member
But how much less? 2%, 5% 10%?
we are still only guessing in regard to reltaive absorption of real growign plants. and then canopy penetration of different colors. lots of factors. just saying anecdotally if im running purples i reduce my measured ppfd by around 10%. too much monos seems to put them on roids which is fine when they can handle it but ive seen adverse effects crop up relative to same ppfd of white light. obviously thats a HUGE oversimpification but it works in my garden
 

Rocket Soul

Well-Known Member
The efficiency on the spec sheet is is for 400-700nm, theres a fair bit of far red in that spectrum. They are also rated at 85C which would seem like higher operating temp than what people normally have. So efficiency will maybe be slightly higher. But still looks lower than luga if i remember right. I would only see this as something for enriching a 80cri spectrum or maybe for vegging under low intensities where targeted spectrum seems to matter more.
 

Rahz

Well-Known Member
we are still only guessing in regard to reltaive absorption of real growign plants. and then canopy penetration of different colors. lots of factors. just saying anecdotally if im running purples i reduce my measured ppfd by around 10%. too much monos seems to put them on roids which is fine when they can handle it but ive seen adverse effects crop up relative to same ppfd of white light. obviously thats a HUGE oversimpification but it works in my garden
I'd sure like to see a test with similar light spreads, umol -vs- umol.
 

Abiqua

Well-Known Member
exactly but
a)most spectrums havent been digitized and analyzed
2)ypf correction is still based off 30 year old absorbance data of leaves in test tubes
Your not gonna like this, but so what?....
Remind me how single nms being digitized and analyzed has anything to do with measuring its plant morphology reaction, you say it like something exists, lol....dont be disingenuous by trying to act like there is an invivo measurement for either parameter, then we can argue....

Ypf has more recent work available, not that makes me more of a supporter, just think it will be a better measure over time...that was the gist of the persusasion....otherwise link a statement that correlates ppf to ypf, does it exist in a practical format?

side note:
Android needs to be added to the dustbin of history, truly a shitty hack on the Ux ....Ps
 
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CobKits

Well-Known Member
post didnt bother me!

sounds like you might be having a bad phone day? hope it gets better!

i was talking particularly about the blurple cobs -has anybody digitized the spectra

im not super up on plant morphology, just putting out there that that absorbance data has its limitations. Im surprised there hasnt been some more advanced studies in that time, if there are can you link them, thanks
 

bleepboop

Well-Known Member
Sorry to resurrect an old thread.

Thought it worth mentioning that I threw together a couple of fixtures with the Sunplus "rose" 1825 chips (red line below) and they worked out fine enough. certainly not an efficient use of power but a nice enough spectrum. The BJB holders for Citizen CLU058 fit them.

Running a pair as supplements in a 2x5x3 space from a hlg-240h-54a at lowish output.

In peak summer I dialed them back to 6hrs in the middle of the the light cycle to keep the heat down as it was peaking about 100f with outside temps of 91f. Other light pictured is a lm301b double row 2ft strip and above was 2x 3k lm561c folux qb288 panels. the folux panels had strings start dying after 12-18 months so they're getting retired for a new strip build. I don't know if it was foliar residue that starting breaking the folux or they're just not very good. A 2x5x3 space is a bit short but the coverage from each far side seems to help manage height and increase canopy penetration.

I know it's definitely a product line that's going to be quickly forgotten in the wake of 3&4umol/j and high cri products from cree/samsung/nichia/ssc but this particular chip isn't quite as blurple as things might initially appear and it was fun enough making a more unusual red supplement.


sunplusrosecurve.pngdurban tibet hp 72 - Copy.jpgsunplusrose.pngblp klp bx F2.jpg
 
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Airwalker16

Well-Known Member
Wish i had seen these a week ago. I picked up some cree cmt-2890's and a couple of 12" Horticultural strips from thomas research last week. May have to make a mini light with those strips and give one of those cobs a spot in the middle.
Could you post some pics of the Thomas Strips? I saw those months ago on DigiKey. Wanted to see real life pics of them. Lit up preferably too if you can?
 
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