I switched from High Pressure Sodium to COBs. My experience

[Carraxe]

After 20 years growing indoors, two years ago I decided to replace my old lighting kits (Sodium lamps with magnetic ballasts and adjust-a-wings) with COBs.

Theoretically, one can replace 600W of sodium with 400 W of Cree or Citizen high quality COBS and get the same amount of weed. At the same time, electricity bill and heat generated reduces.

So I built some kits I bought with Citizen and Cree chips. I replaced 600W sodium with 600 Watt COBs and I chose 3500ºK for all purpose grow, to be used both in flower and in vegetative.
After a couple of years getting used to the cobs, I can say the next positive things I enjoyed:

-I got a better production per watt
-Plants mature between a week and ten days earlier than with Sodium.
-I got less heat, so ventilation needs are reduced.
-Better light distribution and homogeneity.
-Bushier plants. They stretch very little and the distance between branches is kept to a minimum. Branch grow is encouraged and vertical growth limited. It is magic for the extreme sativas that I grow.
-Stronger plants. Stems and branches are stronger.

But I am aware also of some aspects I hope I knew before. There are some questions that can make the change to LEDs a little tricky. These are my impressions. Some are due to the technology, but another can be caused by the specific temperature I used (3500ºK)

-The buds lose bag appeal. In some way, they are leafier than those of the same strains under high pressure.
-Vegetative growth is slower. I don't know if it happens because the lower temperatures in winter (COBs don't heat as much as sodium) or just because they provide different spectrum that doesn't stimulate vertical growth.


I wanted to upgrade my setup, but now I believe that I'll get better results with some sodium mixed with my LEDs instead rising the power with more LEDs. I think that LED anti-stretch spectrum is very nice to be used during the first 1-3 weeks of stretch to avoid explosive growth, but some red and heat from the sodium can help compact the buds during the next weeks.


I think that is clear that 3500ºK is not the right color temperature for flowering, but I doubt that 3000ºK is going to make a big difference.
Some ideas? Thanks

 

[Weezard]

Yeah, I got 2 cents.
The inter-node distance is related to color temperature.
But white cobs waste energy producing photons that are not easily used by cannabis.
And are not adjustable for color temp.

I use blurple leds. They get more bhang for your buck.

Plants CAN, and do use green and yellow light but it is quite inefficient.
I use only red and blue, DIY, adjustable led arrays.
The red:blue ratio is fully adjustable.


When I want stretch, I turn up the red. Too lanky? I turn down the red and increase the blue.
That make them squat and fat leaved.
All the power used creates only 657nm. red, and 435nm. blue
Those are the two absorption peaks for cannabis.

So, I get maximum photon absorption for less power input AND almost total control of morphology.
When I'm not meddling with morphology, I "tune" the light to the plant by changing the ratio until the leaves look black.
Maximum absorption


Tried white cobs a while back and was disappointed.

Aloha,
Weeze

 

[Carraxe]

Nice input.

About the specific spectrum, yes, I was thinking about choosing different spectra and build my own, but COBs were easier. Anyway, I can't say I am disappointed with them, all in the contrary I'm very happy but I wanted to clarify some terms.


What about the leafy buds? Can you avoid that using a warmer spectrum? I am curious because I've seen really compact buds grown using Metal Halide and colder temperatures than I use, and I also expect nice compaction (less leaves) using Sodium.

Cheers

 

[noknees]

https://www.rapidled.com/citizen-amber-cob-clu048-1212c4-22al1k3/

 

[TychoMonolyth]

This is the thread I've been looking for.

Do you think supplemental heat like a small heater would help?

 

[Carraxe]

This is the thread I've been looking for.

Do you think supplemental heat like a small heater would help?

You mean the heater would make the plants to compact their buds? I don't think so, but I guess the plants would grow more. This winter I had temperatures indoor around 15ºC and they were growing very slowly. With sodium lamps the "lights on" temperature was quite higher.

Anyway, I don't see the need of a heater while I can have both heat and a good flowering spectrum with a sodium lamp.

Cheers

 

[Mr D]

After 20 years growing indoors, two years ago I decided to replace my old lighting kits (Sodium lamps with magnetic ballasts and adjust-a-wings) with COBs.

Theoretically, one can replace 600W of sodium with 400 W of Cree or Citizen high quality COBS and get the same amount of weed. At the same time, electricity bill and heat generated reduces.

So I built some kits I bought with Citizen and Cree chips. I replaced 600W sodium with 600 Watt COBs and I chose 3500ºK for all purpose grow, to be used both in flower and in vegetative.
After a couple of years getting used to the cobs, I can say the next positive things I enjoyed:

-I got a better production per watt
-Plants mature between a week and ten days earlier than with Sodium.
-I got less heat, so ventilation needs are reduced.
-Better light distribution and homogeneity.
-Bushier plants. They stretch very little and the distance between branches is kept to a minimum. Branch grow is encouraged and vertical growth limited. It is magic for the extreme sativas that I grow.
-Stronger plants. Stems and branches are stronger.

But I am aware also of some aspects I hope I knew before. There are some questions that can make the change to LEDs a little tricky. These are my impressions. Some are due to the technology, but another can be caused by the specific temperature I used (3500ºK)

-The buds lose bag appeal. In some way, they are leafier than those of the same strains under high pressure.
-Vegetative growth is slower. I don't know if it happens because the lower temperatures in winter (COBs don't heat as much as sodium) or just because they provide different spectrum that doesn't stimulate vertical growth.


I wanted to upgrade my setup, but now I believe that I'll get better results with some sodium mixed with my LEDs instead rising the power with more LEDs. I think that LED anti-stretch spectrum is very nice to be used during the first 1-3 weeks of stretch to avoid explosive growth, but some red and heat from the sodium can help compact the buds during the next weeks.


I think that is clear that 3500ºK is not the right color temperature for flowering, but I doubt that 3000ºK is going to make a big difference.
Some ideas? Thanks

2200K COB's are available.

https://www.cree.com/led-components/media/documents/ds-XHG.pdf



Beware..... LED blue light spectrum 450 nanometer (nm) frequency is very damaging to your eyes. Always wear eye protection.

 

[indagroove]

2200K COB's are available.

https://www.cree.com/led-components/media/documents/ds-XHG.pdf



Beware..... LED blue light spectrum 450 nanometer (nm) frequency is very damaging to your eyes. Always wear eye protection.

Is there a reason to consider these over the Cree 3590?..

https://www.cree.com/led-components/media/documents/ds-CXB3590.pdf

 

[Mr D]

Is there a reason to consider these over the Cree 3590?..

https://www.cree.com/led-components/media/documents/ds-CXB3590.pdf

Not that I know, of especially if the lumen per watt output is higher.

 

[Carraxe]

2200K COB's are available.

https://www.cree.com/led-components/media/documents/ds-XHG.pdf

Beware..... LED blue light spectrum 450 nanometer (nm) frequency is very damaging to your eyes. Always wear eye protection.

As I've said before, I've seen good compact buds coming both from high and low temperature of color from different discharge lamps. That's why I believe the reason for differences in bud compactness are caused by changes in a different part of the spectrum than the red and blue. What I think? It could be the reaction to the far red spectrum, I guess Sodium has this covered. Heat? It could also be.

I don't think lowering the color temp of the COBs it is the solution, and this low temp would make these COBs quite terrible for vegetative.

Cheers

 

[Weezard]

For tight buds, just add a little nitrogen during flower.
Just a little though. Too much makes the buds tight but small.

 

[Mr D]

As I've said before, I've seen good compact buds coming both from high and low temperature of color from different discharge lamps. That's why I believe the reason for differences in bud compactness are caused by changes in a different part of the spectrum than the red and blue. What I think? It could be the reaction to the far red spectrum, I guess Sodium has this covered. Heat? It could also be.

I don't think lowering the color temp of the COBs it is the solution, and this low temp would make these COBs quite terrible for vegetative.

Cheers

I guess I misunderstood your post.

I started out in '98 with MH and eventually a mix of MH and HPS. More recently 3500K LED strips with the addition of red and blue LED strips totaling up to 550 watts. I've used LED alone and in combination with CMH, HPS and MH. During the coldest months I have to fire up the 400 watt MH to keep the flower room temps in range. Or use a space heater.

Like you I have noted what seems to be faster flowering under straight LED's. However I have always found bud compactness to be largely strain dependent. Not to say you can't make some tweaks to lighting and or nutes get slightly better results. I just haven't seen any significant differences in a given strain due to the type of lighting used all things being equal.


However I'm always open to learning something new.

 

[Carraxe]

For tight buds, just add a little nitrogen during flower.
Just a little though. Too much makes the buds tight but small.

I guess I misunderstood your post.

I started out in '98 with MH and eventually a mix of MH and HPS. More recently 3500K LED strips with the addition of red and blue LED strips totaling up to 550 watts. I've used LED alone and in combination with CMH, HPS and MH. During the coldest months I have to fire up the 400 watt MH to keep the flower room temps in range. Or use a space heater.

Like you I have noted what seems to be faster flowering under straight LED's. However I have always found bud compactness to be largely strain dependent. Not to say you can't make some tweaks to lighting and or nutes get slightly better results. I just haven't seen any significant differences in a given strain due to the type of lighting used all things being equal.


However I'm always open to learning something new.

Most of the strains I grow now were also grown in my setup when I had the High Pressure Sodium lamps, so I don't think that this difference in bud tightness is a dietary issue or a genetic one.

I find the buds in my Jack Herer, for example, to be less dense, fluffier, while they still rock. There are some small differences I realize about because I've been growing this cut for near a decade and I know it well.

It is difficult to see the changes in SSSDH due to its special bud shape. This one flowers very very well under COBs and I save more than a full week time.

But I can say I had real problems with more extreme sativas like Red Snake and Angola Thai, because at 12/12 the buds never fatten and just keep stretching. And I had no problems with 12/12 with sodium. I had to find a solution for that, that I finally did.

Cheers

 

[GOT_BUD?]

I have the fortune of being able to grow under both COBs and and an LED panel with added red. I've only got a few grows under my belt with both. But I've run the same plants under both.

The enhanced spectrum panels (added red) produced more flower and less leaf with 2 different strains.

I'm about to run a third strain under the panels that I just completed a grow with under my COBs, and I'm fairly certain the enhanced spectrum is going to boost flower production again.

If this plant grows the way I think it will under the panel, I will be adding some 630 and 660 nm LEDs to my COB rigs in short order.

ETA - My COBs are 3500K Vero 29s.

 

[Ichabod Crane]

Loose buds under LEDs is not the LED. These were grown under 3000K samsung 301B's.

Deathstar



True OG One ounce per jar.



Left two are CBanana and Low Rider are the right two. Also one ounce per jar.



A upper of CBanana



The average weight here is around 13 grams per cola.

 

[Carraxe]

Loose buds under LEDs is not the LED. These were grown under 3000K samsung 301B's.

Deathstar

View Image

True OG One ounce per jar.

View Image

Left two are CBanana and Low Rider are the right two. Also one ounce per jar.

View Image

A upper of CBanana

View Image

The average weight here is around 13 grams per cola.

View Image

I don't think you understood the meaning of my posts.

This is under 3500ºK COBs:





That's not loose, is it?

 

[Ichabod Crane]

I don't think you understood the meaning of my posts.

This is under 3500ºK COBs:


[URL=https://www.icmag.com/ic/picture.php?albumid=79842&pictureid=1934169&thumb=1]View Image[/URL][URL=https://www.icmag.com/ic/picture.php?albumid=42683&pictureid=1955048&thumb=1]View Image[/URL]


That's not loose, is it?

I can not really tell from a picture. But no it does not look loose.

I may have misunderstood you. But I dont see more leaf under my LED than I do under HPS. I trim heavily under both ways to reduce as much trimming latter in flower as I can. This leads to less leaf and bigger buds.

 

[Carraxe]

I can not really tell from a picture. But no it does not look loose.

I may have misunderstood you. But I dont see more leaf under my LED than I do under HPS. I trim heavily under both ways to reduce as much trimming latter in flower as I can. This leads to less leaf and bigger buds.

I find some subtle differences, I wouldn't say buds under LEDs are leafier, but I'd rather say that in some way they are somehow slightly airier: stretchier, less dense.
But I guess it depends on the strain, specially with sativa leaning ones. This is just a question of fine tuning, most of the buds I grow are extremely satisfying.

Cheers

 

[TychoMonolyth]

... I trim heavily under both ways to reduce as much trimming latter in flower as I can. This leads to less leaf and bigger buds.

Are you saying you trim the sugar leaves in the colas as it grows? That sounds interesting.

 

[Douglas.Curtis]

I find some subtle differences, I wouldn't say buds under LEDs are leafier, but I'd rather say that in some way they are somehow slightly airier: stretchier, less dense.

Completely spectrum and environment related. I have no problems with dense, low-leaf, HPS style flowers under the Mars Hydro TS spectrum.

But I guess it depends on the strain, specially with sativa leaning ones. This is just a question of fine tuning, most of the buds I grow are extremely satisfying.
Cheers

Same strains, under both HPS and LED, turned out perfectly fine. Even with excess light at first, the LEDs still produced great flowers like the HPS.

LEDs really hinge on the spectrum. With the additional far-red in your lights, your flowering times are a bit shorter and your plants will be more 'stretched.' You can decrease your night hours a bit, until you're hitting the same flowering time again. You'll have a higher yield.

Want to see the differences between different LED spectrums? Here's a good thread for it... "Show Your LED Flowers..." Pay attention to what the flowers look like, and the spectrums the growers are using to achieve them. This is a good starting point.