DiY LED - Cree XPE XTE XML2 - Luxeon ES - Oslon SSL

SupraSPL said:

Sweet setup! Which drivers did you decide on? I am curious about every part of your design do you have a thread going?

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The drivers are from Satisled, there are some 350mA/120V and some 450mA/80V. I will start some thread later about building with the Vero 10's.

Since the lamps are 41% efficient, that works out to 123 PAR watts/m2 (a bit less due to stray photons).
In order to take this any further and convert to PPFD, we would need to take spectrum into consideration again

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You can multiply the watt/m2 figure by 5 to get an estimate for the umols (for a normal balanced spectrum). In your case it would be about 600 umol/m2/s.

Hey Supra how is the canopy penetration of one module at 700mA?

For my standards of decent buds worth trimming, Id say only 12". The 600 HPS is 18-24" so canopy management and light placement is more important with LED, especially bare LEDs. It would be very easy to add side lighting if a taller canopy is needed but I have not tried it yet. That would be a more efficient use of space and would require a lot less canopy management.

For vegging 700mA (2watts) is good for at least 24"

Reworked some of my spreadsheets and found a few errors. The Oslon SSL deep red 3T is 39% not 42%. The 4T is 44.3% not 48%. The overall lamp is 39% efficient, not 42%.

43 days

From left to right its Ace of Spades, Holy Grail Kush, Kandy Kush and another of the same clone Kandy Kush. Hiding behind them are a pair of SSSDH Shire and another Kandy Kush. The leaves arent that yellow yet its the HPS coloring.

If you want to increase your LEDs efficiency and life span, you should add a fan to each heatsink. The heatsinks you are using are not made for natural convection, but forced convection.

They do get some airflow from the circulation fan but these lamps were designed specifically to not require active cooling (110 sq cm/watt). The space between the fins is large enough for passive cooling (.4")

The heatsink temps stabilize at about 30C with an ambient temp of 24C. Not much room for improvement there. That means junction temps are at or below 50C. With a Tj of 50C the LEDs will suffer virtually no lumen depreciation whatsoever (<4% in 10 years).

As nice as that is it comes at a significant cost for materials. Each heatsink is 6 LBs of aluminum and cost $40. On the other hand the lamps pay for themselves in 1 month. I prefer the simplicity and efficiency of passive cooling and I suspect that this design runs cooler than most commercial LEDs that use active cooling because they will not spend on large heatsinks.

Hey man great looking light and super bomb looking kolas you got growing.

SupraSPL said:

They do get some airflow from the circulation fan but these lamps were designed specifically to not require active cooling (110 sq cm/watt). The space between the fins is large enough for passive cooling (.4")

The heatsink temps stabilize at about 30C with an ambient temp of 24C. Not much room for improvement there. That means junction temps are at or below 50C. With a Tj of 50C the LEDs will suffer virtually no lumen depreciation whatsoever (<4% in 10 years).

As nice as that is it comes at a significant cost for materials. Each heatsink is 6 LBs of aluminum and cost $40. On the other hand the lamps pay for themselves in 1 month. I prefer the simplicity and efficiency of passive cooling and I suspect that this design runs cooler than most commercial LEDs that use active cooling because they will not spend on large heatsinks.

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.4" (10mm) isn't that bad - looked smaller on the pictures At 10mm your convection constant is 2, while free convection happens at a constant of 2.5. So yea, not much to improve there.
Active cooling a great way to reduce the need for expensive materials like aluminium, so that is indeed what commercial lamps are using.


Another way to increase the cooling capacity of the heatsinks, are to coat them in black paint (thin layer). This will greatly increase the emissivity, but since your temps are already quite low, the gain might be quite small.

Out of curiosity I turned the ceiling fan off for a few hours. Ambient rose from 22C to 28C and average heatsink temps stabilized at 40C. Turned the ceiling fan back on and heatsink temps are down to 32C. That is partly due to airflow in and near the fins and partly due to a decrease in ambient temp.

For reference this setup is running at about 102 sq cm/watt and overall efficiency is about 39% those are the kind of temps you can expect.

9 weeks and the Kandy Kush is definitely living up to its pedigree because the room can be described as a trainwreck. Shire is also very floppy they were all supporting each other and tangled together. Moving them to the dark room/trimming room was a very stinky process. There are still some white pistils on the bigger colas but the frosting is ripe and the nugs are dense so it is time for them to hang out in the dark room for a day or 2. Overall batch looks like it will be a nice turnout, 2 weeks until I get the weight numbers.


The Kandy Kush impressed me last time and I am glad I ran 3 of them this time and will definitely run it again. The smell is a balance between chem, diesel and OG. Yield and density is good, frosting is very good and potency is excellent.


The Shire really likes LED. It finishes quicker, gets frostier and smell is stronger and better. Smells like lemony, diesel, playdoh, pine. Yield is good and potency is excellent.


The Holy Grail Kush turned out very good. Excellent top notch OG aroma. Yield is medium, frosting is good, density is excellent, potency is excellent.

Next batch in the LED room, now 320W. These ladies got way too big I will have to use height control topping and bending. Vegged up in 80W LED room. 8 buckets instead of 7 this time so yield should be a bit better.

DNA - Stacked Kush fem
DNA - La Cocolate fem
Reserva Privada - OG18 fem
HSO - Blue Dream fem
Cali Connection - Original Sour D fem
TH Seeds - Darkstar fem
TGA - Qleaner
Sweet Seeds - Green Poison fem

I like the new lineup. Alot of strains ive had my eye on but never felt like running so ill be watching closely.

A few dry nug pics from that run. Messing around with new cam.

Reservoir Seeds SSSDH The Shire cut
DNA Holy Grail Kush

Reserva Privada Kandy Kush

Jars have already been ravaged. KK, Shire, HGK

Hi, whats this purple coming from in your Kandy Cush pics.
Strain dependant, lack of nutes, harvest time sign?

lax123 said:

Hi, whats this purple coming from in your Kandy Cush pics.
Strain dependant, lack of nutes, harvest time sign?

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Kandy kush naturally gets purple from genetics, in sure thats part of it

Good work! It would be interesting to see how your existing array worked with those 3070's supplemented in?

Kandy Kush macro looks lovely mate!

That tent gets the coldest during lights out because the cold air intake is in there. The 450nm blue LEDs also increase anthocyanins very noticeably.
OG18

Hi,
thank you.
Very interesting for me since i have something similar in my first grow and cant exactly point out the cause.
Which is important in respect of learning something from my first to grow to avoid mistakes the next time.


I im growing 4x unknown strain. Day 55 of flower, purpling started last 2,5 weeks, but the biggest of them just getting purple in the last week.

From the plant that it most purple i made a toppling from (when the plant was totally green in veg) and replanted it in a new pot.
But its not showing this purpling, so i wondered what the heck -doesnt seem to be an obvious trait of this strain.


So i wondered if my DIY spectrum is maybe bad and causing that or i overferted or something like that.

Are blue leds overloading the photosythesis stressing the plant to produce more anthocyanins to defend itself from oxidants/ free radicals?
I guess thats would be very bad?
On the other hand im growing a skunk in the same environment its not showing purple at all

But then its also intriguing that one plant isnt getting purple all around but just at those buds closest to my panel, but spreading.
(compare picture 2 and 3 and 4. Its the same plant, 3rd picture shows the side that has the most distance from the panel, almost no purple at all)
-Just like in your picture, one side totally purple, the other one still perfectly green.


In the matter of led i only always read about "bleaching" from blue, but purple isnt exactly the same, is it.
Im using mostly WW, CW and Red leds in like 5:2:3

But if the led itsself are the cause, i thought id probably have seen waaaay more pictures of something like this in LED and DIY Led grows.
My temps are like 19°C-25°C. I read purple is usually caused by way cooler temps.

Id really like to get to the bottom of this