LED Help - Please don't hate me ;-)

[Rahz]

Really? Wonder whose pulling those numbers. So like 4 pounds off 1000 watts of cob?

VeroV2 can pull those numbers with the right strain and a good grow. Anyone using 3590s should be pulling that unless they're doing something wrong. Realistically with 3590s you should be shooting for around 5 if growing hydro with 750-800 PPFD.

 

[giantsfan24]

I didn't think my yield from my 400w was that spectacular....I bent (LST), defoliated..vegged for a little longer than I had in previous grows. Very little in fan leaves and all really nice bud. That was 3 plants, 20" tall. They were beautiful plants. That was spring 2013 and I'm still smoking it. It's great weed.

Anyway, yes I'd like to make the change to give me more options throughout the year. With the HID, I had only the coldest time of year to grow due to the box location in my garage. The heat off the HID would serve as needed heat during a time of year where ambient temps are colder but that's about the only time. 90 day window is all can really count on. With LED I'm hoping to lengthen that out to two cycles rather than just one.



,

 

[giantsfan24]

Is it correct that this is viewed like HID with regard to Kelvin temps?

Like for instance, 2700k for flower, 5000k for veg?

 

[BigZcolorado]

I lurked around in the DIY for awhile then just went with a prebuild light for the warranty. Based on the results I'm seeing with the Johnson Grow Lights CX-9 I bought, I think a CX-4 would do well in there and its in the price range you mentioned. I think there may even be a coupon code around here somewhere.

my post with the CX-9 https://www.rollitup.org/t/johnsongrowlights-com-cx-9-grow.894034/page-2#post-12275085

 

[littlejacob]

I didn't think my yield from my 400w was that spectacular....I bent (LST), defoliated..vegged for a little longer than I had in previous grows. Very little in fan leaves and all really nice bud. That was 3 plants, 20" tall. They were beautiful plants. That was spring 2013 and I'm still smoking it. It's great weed.

Anyway, yes I'd like to make the change to give me more options throughout the year. With the HID, I had only the coldest time of year to grow due to the box location in my garage. The heat off the HID would serve as needed heat during a time of year where ambient temps are colder but that's about the only time. 90 day window is all can really count on. With LED I'm hoping to lengthen that out to two cycles rather than just one.



,

Bonjour
Do you live in a desert?
Woww it must be really hot where you live
But with 2 bars of 4 cob it will be colder!
CU

 

[littlejacob]

Is it correct that this is viewed like HID with regard to Kelvin temps?

Like for instance, 2700k for flower, 5000k for veg?

Bonjour
You can do it all along with 3500ºk...good vegg and wonderfull bloom
Or you go 5000ºk for vegg and 3500ºk for bloom!
The first option is the best if you do not have a vegg box
CU

 

[littlejacob]

I changed because 4 cobs looks better than purple led. And they're bright as #@!&. But I definitely understand heat. My 600w hps gets cut to 75% and sometimes 50% during summer to keep temps at 85℉.

4 x crees @ 50w each. 2 5000k, 2 3000k in the same space. (2'7"x2'7"x4'11)
View attachment 3594687

Bonjour
Do you use the 5000ºk for vegg then you add the 3000ºk?
Do you see any differences between 3000 & 5000ºk? (In bloom)
Is it more frosty under 5000ºk?
Do you move the plants or lights?
CU

 

[giantsfan24]

Bonjour
You can do it all along with 3500ºk...good vegg and wonderfull bloom
Or you go 5000ºk for vegg and 3500ºk for bloom!
The first option is the best if you do not have a vegg box
CU

That's what I thought I was reading. With HID, I had one bulb for veg and another for flower. Seems so archaic compared to cob's lol.

Bonjour
Do you live in a desert?
Woww it must be really hot where you live
But with 2 bars of 4 cob it will be colder!
CU

No not in the desert but with them temps so high in such a small space, just a little bump in the ambient temperature puts the box temp way up. The box location is also part of the issue as it's in my garage.

 

[Atulip]

Both fixtures in the same 2'7"x2'7" tent. They've only been in there 2 weeks now, current plants in there spent the first 7 weeks of flower under a mars2 400, just waiting for them to Amber up then some ~30 day old autos are going in there. Just went with 3000k and 5000k and going to center them for a nice blend of light.

They're actually 2x cxb3590 3000k 72v with 2x cxa1512 6500k(parallel) on one fixture. And 2x cxa3590 5000k 72v with 2x cxa1512 2700k(parallel) on the other. Mainly added the 1512s to soak voltage. Planning to outfit a 2'7"x4'11" tent with 8x cxb3590 4000k 72v. Both of these spaces will be growing autos at all stages of life.

But if I were going for a flowering only space I'd use 3000ks, 5000k for veg, and 3500k for all purpose. Ima go for 4000ks mainly since cutter has the 72v in the DB bin.

 

[giantsfan24]

I saw in another thread some informal testing on the cxb3590 vs. the cxb3070 and, to me, there didn't seem to be much difference between the two. Is there some advantage to the 3590 I'm not seeing for the money?

 

[Atulip]

Efficiency. About 1k lumens more for 3590 vs 3070 Both at 36v 1.4A. Plus the 3590s come in 72v, which lets me run it on the .7A mars drivers for the same light output as the 36v @ 1.4A.

 

[giantsfan24]

Efficiency. About 1k lumens more for 3590 vs 3070 Both at 36v 1.4A. Plus the 3590s come in 72v, which lets me run it on the .7A mars drivers for the same light output as the 36v @ 1.4A.

Great so we're taking about a difference in lumens of what 1% between them roughly? Maybe less??

I don't know what I'm talking about so keep
that in mind lol

 

[Atulip]

That's more like 10%

8.9k lumens vs 8.1k for 3500k cxb3590 and 3070 at their top bins at 1.4A.

 

[giantsfan24]

Are there sources here for cob's? I've read about a guy named Jerry? Kingbrite? Have also seen mouser, digikey. Are those reputable?

 

[littlejacob]

Bonjour
Yes Jerry is a reliable seller cutter too
As for the rest it depend if you are in US or EU or somewhere else!
I do use Jerry for convenience and because he is a nice guy...he have cob holder reflector lenses drivers!
CU

 

[Fastslappy]

Cutter sells 3590 @ the top bin
i've bought 32 from them

 

[giantsfan24]

Cutter sells 3590 @ the top bin
i've bought 32 from them

I'm not sure I really need the 3590. It seems to me that the marginal increase in efficiency isn't worth the extra money over a 3070 in a six cob configuration for my size space and production needs.

If you disagree, please correct me but that's what I think I'm reading. (So far)

 

[Atulip]

Its only ~720 lumens more per cob with cxb3070 BB vs cxb3590 CD 3500k 36v @ 1.4A. +18lumens/watt. With 6 cobs that is like half a cob extra light overall for these cxb3590s.

But considering the price difference of $32 vs $49 per cob. $102 additional cost for the 3590s, I'm probably reconsidering the 3070s now simply because they cut the up front cost down considerably at a marginal decrease in efficiency. 10% decrease in efficiency for a 35% decrease in initial costs.

$102 towards extra electricity "wasted" gets you 850kwh @ $.12 per. 16watts wasted per hour extra, 53,125 hours, 8 years @ 18/6.

So the money saved on 3070s beats the efficiency earned on the 3590s. The only other consideration is increased yield for added lumens but I'm not high enough for that kind of math.

Prices are cutters USD price cob only no shipping. Calculations for a 6 cob fixture 36v@1.4A

TL;DR unless you can get cxb3590s for about $5 more than cxb3070s, the cxb3070s will be a better value overall. At a 2 year lifetime of 18/6.

 

[giantsfan24]

Its only ~720 lumens more per cob with cxb3070 BB vs cxb3590 CD 3500k 36v @ 1.4A. +18lumens/watt. With 6 cobs that is like half a cob extra light overall for these cxb3590s.

But considering the price difference of $32 vs $49 per cob. $102 additional cost for the 3590s, I'm probably reconsidering the 3070s now simply because they cut the up front cost down considerably at a marginal decrease in efficiency. 10% decrease in efficiency for a 35% decrease in initial costs.

$102 towards extra electricity "wasted" gets you 850kwh @ $.12 per. 16watts wasted per hour extra, 53,125 hours, 8 years @ 18/6.

So the money saved on 3070s beats the efficiency earned on the 3590s. The only other consideration is increased yield for added lumens but I'm not high enough for that kind of math.

Prices are cutters USD price cob only no shipping. Calculations for a 6 cob fixture 36v@1.4A

TL;DR unless you can get cxb3590s for about $5 more than cxb3070s, the cxb3070s will be a better value overall. At a 2 year lifetime of 18/6.

Wow! Thanks for that calculation. I just had a sense but you've clearly spelled it out.

As this is a personal grow and my usage is so light, it just doesn't make sense to go deep and get the highest end stuff but get what's adequate and will do the job.

Where did you see the 3070's at $32? I've seen $44.

 

[Atulip]

USD prices. 44 Aud is ~32 USD.

http://www.cutter.com.au/products.php?cat=Cree+CXA/B30xx&pg=2