I switched from High Pressure Sodium to COBs. My experience

Ailalelo

Well-Known Member
I wanted to share a thread I started in a different forum. The idea is to share my experience with as many people as possible.

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.
What do you think? What's the way to improve? Thanks
 

Renfro

Well-Known Member
The buds lose bag appeal. In some way, they are leafier than those of the same strains under high pressure.
I don't grow sativas but I got better bag appeal, more frost and better density with LED. I run 3500K 90 CRI Luminous CXM-22 COB's. Perhaps it's more of a sativa thing?

I liked the 3500K spectrum. On these cob's I get more blue and don't really lose any red compared to the 3000K.

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.
What do you think? What's the way to improve? Thanks
Not really sure what is lacking, perhaps some pics of your flowers from previous runs would enlighten us. I do think the sativa genetics are harder to get the bag appeal from, high leaf to calyx ratio, fox tailing and such are sativa traits that may become more pronounced with the LED setup.
 

Ailalelo

Well-Known Member
What I learnt with COBs is that not all strains react the same way to the change of spectrum. Once you get used to grow a strain for years, it is shocking to see how the plants behave like if they were different ones. The most obvious one is my Jack Herer. I have some pictures from the times I used Sodium only. Saddly, I don't have recent pictures from under the COBs. But I'll take them as soon as I can.

Hard dense buds with little trimming. That's a real jewel.

IMGP3994.JPGIMGP3999.JPG


Other strains, like Taskenti or Black Domina doesn't seem to be concerned by the change. It is a mostly sativa thing.
Cheers
 

TerrapinBlazin

Well-Known Member
Great thread. I’m enjoying running my HPS in a passive air cooled hood during the winter because of its nice heat output, but I want to build a cob light for when it starts to warm up. I’m looking at those citizen chips because they’re cheap. The main reason I haven’t wanted to build a cob light was because I didn’t want to pay 40-50 bucks a chip for cxb3590s
 

Ailalelo

Well-Known Member
Great thread. I’m enjoying running my HPS in a passive air cooled hood during the winter because of its nice heat output, but I want to build a cob light for when it starts to warm up. I’m looking at those citizen chips because they’re cheap. The main reason I haven’t wanted to build a cob light was because I didn’t want to pay 40-50 bucks a chip for cxb3590s
Then you might go with the Citizen. I started spending money on Cree but later I realized you can push the Citizen up to +100W each and they keep a good working regime. Now I'd setup CLU058 at 100W, that's a good power ratio at good specs.

I believe that mixing heat and spectrum of old HPS with new white COBs is what provides the best results in winter in cold places.

Cheers
 

TerrapinBlazin

Well-Known Member
I don’t understand a whole lot about it yet. I read the citizen chips have the highest efficiency around 50 watts so I was thinking 8-10 should get me around what I want. I actually thing 9 in a square arrangement would work the best for my closet. I didn’t think it would be affordable until I discovered the chips. I also want to try one of those quantum boards on a cheap driver for my veg tent. I’ll probably do that project first since it will be cheaper and give me a good feel for building an array.
 

eyderbuddy

Well-Known Member
For Flowering 3000K is king, 3500K is still a good and balanced veg/bloom spectrum, but you're going to have to keep a couple things in mind when switching from the HPS mindset:

- More Cal-Mag (the spectrum stimulates consumption)
- More Leaf matter, Inter-nodal Stacking (again, spectrum)
- Much Less Vertical Growth (spectrum)
- Plants in veg in will grow at about the same speed (photon/photon), but the HPS will look "bigger" because they will stretch more, while the LED ones will stack more node and will look shorter.
 

Florere

Well-Known Member
My harvest and quality went up. Only in the beginning i have difficulty to grow. They all look like they die. Then after a while they go like on steriods
 

TerrapinBlazin

Well-Known Member
Well you all have convinced me. As soon as I have some extra money I’m gonna do a board for my grow tent and a cob light for my closet. I’ll probably be asking a lot of stupid, repetitive questions to ensure I order the right stuff, lol.
 

rob333

Well-Known Member
Well you all have convinced me. As soon as I have some extra money I’m gonna do a board for my grow tent and a cob light for my closet. I’ll probably be asking a lot of stupid, repetitive questions to ensure I order the right stuff, lol.
well this is my first led pull and im fucking impressed
 

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rob333

Well-Known Member
I am excited for my new QBs to arrive now.... and here I was going to just buy new digital ballasts and call it a day...
i cant say you will get that with qb's but as for 300 w of solskin yes i reckon ill come in around a pound and 4 oz off 300w of led that is fucking crazy
 

TerrapinBlazin

Well-Known Member
I think a 100 watt quantum board should be plenty for a 3x3 tent, right? So board, heatsink, and wiring is obvious but I’m having a little harder time figuring out which driver to get. Do I want something a little more powerful than 100 watts so I can turn it down?
 

JohnDee

Well-Known Member
Hi Al,
I agree with the mixed spectra idea. Did MH and HPS together back in the day. Now use cmh and led. About 600w of each.

I think a 100 watt quantum board should be plenty for a 3x3 tent, right? So board, heatsink, and wiring is obvious but I’m having a little harder time figuring out which driver to get. Do I want something a little more powerful than 100 watts so I can turn it down?
For a 3x3 using 30watts/sf you would want way more then 100w. My math shows 270w minimum.
JD
 

coreywebster

Well-Known Member
for veg only. I will not be flowering under the board. I have a closet set up for flowering and I want to have at least 500 watts of 3000k cobs
If its just for veg then get a 4 pack of hlg QB132s and a hlg 120h-c1050a driver and wire in series. Should give 140 ish watts.

That will give you better light spread over a 3x3 than a single board which would be intense in the centre and weak on the outsides.
They also do not need heatsinks and you can dim
 
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