Another Cree CXB3590 DIY thread

littlejacob

littlejacob

Well-Known Member
Bonjour
I am more than happy...I am impressed!
And take care about nutes...need less than with hps...lot less...I had nutes burn with 3ml/L biogrow on bushy 1 foot plant...so be careful!
For the distance from the cob...it depend on how hard I push them...I have the b version of hlg-185-1400 so from now I never use more than 60% of the lights...about 120w to vegg a 3.5x3.5(at least for the 3/4 first weeks with a bending at day 20!)
So...10cm (4 inches) at 30% of max and now 20cm (8 inches) and when I am going to use it at max 30cm (12inches) maybe a bit more!
But I have 4 separate panels 250x165x35mm (10x6.6x1.4 inch) with a 120mm fan on each (dimmable from 4.5V to 12V)@4.5V so I have a better spread of light...I split the box in four and I put a panel at the center of each quarter! I have cheap mylar on my wall...I don't know the English for this...emergency towels, things fire man use! There is two side a Silver and a gold (the gold is reflective) but it is ok for only 200w!
I was planning to add my chinese led during bloom because of the 200w...not enough I was thinking...but now I really want to try this way!
To know how much I can pull from it!
But I definitely add 4 cxb 3590 3500ºk and some 5000ºk or 6500ºk to my Xmas wish list(maybe santa would have built this for me)
Have a great day ★
 
Humanrob

Humanrob

Well-Known Member
@captainmorgan -- Do you calculate your grams per watt after each grow? Do you grow with that more as your benchmark, or are you more interested in the total weight? I've been thinking about this, and I imagine there is a bell curve to adding more lights. If doubling the watts only increases the total weight output by 50% (as a random example), then for someone production minded that's worth it. But if you are efficiency oriented, and grams per watt is your ultimate goal, then the sweet spot would probably be back down the curve somewhere? Just curious what your focus is, if you have one. :)

I think in comparing the 3070 and 3590 grows, g/w will be an interesting comparison point.
 
ttystikk

ttystikk

Well-Known Member
Humanrob said:
@captainmorgan -- Do you calculate your grams per watt after each grow? Do you grow with that more as your benchmark, or are you more interested in the total weight? I've been thinking about this, and I imagine there is a bell curve to adding more lights. If doubling the watts only increases the total weight output by 50% (as a random example), then for someone production minded that's worth it. But if you are efficiency oriented, and grams per watt is your ultimate goal, then the sweet spot would probably be back down the curve somewhere? Just curious what your focus is, if you have one. :)

I think in comparing the 3070 and 3590 grows, g/w will be an interesting comparison point.
Click to expand...
Here's your curve;
PPFD2.jpg

To be more specific, I'd characterize this plot as 'asymptotic', that is, approaching an ideal value without ever quite touching it.

If you want more grams per watt, you run low light pressures to the left. If you want maximum yield, you go as far to the right as possible.

Most growers want the best possible combination of the two and find that somewhere around 8-900 PPfd is the 'sweet spot'. Another sweet spot appears to be right around 1200 PPfd. While many lighting systems on the market can certainly exceed even double these levels, it's hard for most to deliver it evenly across a canopy while avoiding hot spots.
 
Humanrob

Humanrob

Well-Known Member
ttystikk said:
To be more specific, I'd characterize this plot as 'asymptotic', that is, approaching an ideal value without ever quite touching it.

If you want more grams per watt, you run low light pressures to the left. If you want maximum yield, you go as far to the right as possible.

Most growers want the best possible combination of the two and find that somewhere around 8-900 PPfd is the 'sweet spot'. Another sweet spot appears to be right around 1200 PPfd. While many lighting systems on the market can certainly exceed even double these levels, it's hard for most to deliver it evenly across a canopy while avoiding hot spots.
Click to expand...
Thanks for that info. I'm a long way from being a "master grower" and haven't gone as far as to calculate my PPfd (honestly, I only conceptually know what that references). In my simplified world of trying to balance grow medium, water, light, and nutes, I'm focused mostly on overall yield as my measure of success, with grams per watt being a reference for how efficiently I'm going about it. There are so many variables, I can't imagine how many grows I'll have to do before I can turn up/down my dimmers a percentage between grows, and see a predictable change in outcomes. Some day maybe I'll have everything else nailed down, and the light itself with be the only remaining variable.

I am curious among those I consider to be the elite growers, what their focus and goals are. When they tweak their well honed system, what specifically are they trying to improve? Most of the conversations seem to be about weight (either overall or in relation to watts), I'm also curious how light effects THC content. That's probably being discussed somewhere, I'm probably spending too much time in the DIY threads...
 
ttystikk

ttystikk

Well-Known Member
Humanrob said:
Thanks for that info. I'm a long way from being a "master grower" and haven't gone as far as to calculate my PPfd (honestly, I only conceptually know what that references). In my simplified world of trying to balance grow medium, water, light, and nutes, I'm focused mostly on overall yield as my measure of success, with grams per watt being a reference for how efficiently I'm going about it. There are so many variables, I can't imagine how many grows I'll have to do before I can turn up/down my dimmers a percentage between grows, and see a predictable change in outcomes. Some day maybe I'll have everything else nailed down, and the light itself with be the only remaining variable.

I am curious among those I consider to be the elite growers, what their focus and goals are. When they tweak their well honed system, what specifically are they trying to improve? Most of the conversations seem to be about weight (either overall or in relation to watts), I'm also curious how light effects THC content. That's probably being discussed somewhere, I'm probably spending too much time in the DIY threads...
Click to expand...
Yield is one variable with as many approaches as people to give you advice- and quality is another, lol

The list of variables is endless so you want to learn to spot trends.

If your plan is to use COB LED to improve your yield per watt, I'd say it's a solid plan. I'd suggest spending a bit more to get better efficiency, at least in the fifties.
 
captainmorgan

captainmorgan

Well-Known Member
AlbinoAcorn said:
Nice setup. What's the closest you get those LEDs to the plants?
Click to expand...
I haven't tried to see how close they can go because of the lights design,the sweet spot is probably 8" to 12" for my set up.

Meinolf said:
Has this been adressed before?: Which nutes at which EC do you give?
Click to expand...
Veg + Bloom and cal/mag at 500 to 600 ppm for the strains I'm running.

Humanrob said:
@captainmorgan -- Do you calculate your grams per watt after each grow? Do you grow with that more as your benchmark, or are you more interested in the total weight? I've been thinking about this, and I imagine there is a bell curve to adding more lights. If doubling the watts only increases the total weight output by 50% (as a random example), then for someone production minded that's worth it. But if you are efficiency oriented, and grams per watt is your ultimate goal, then the sweet spot would probably be back down the curve somewhere? Just curious what your focus is, if you have one. :)

I think in comparing the 3070 and 3590 grows, g/w will be an interesting comparison point.
Click to expand...
GPW is what I use as a gage for my own grows and I think my set up is nearing a max output but I'll see what this new light is capable of in the next couple grows. I'm one that believes PPFD should be matched to your grow style and you don't need 1000 PPFD on a scrog. I can get in the 2 GPW range with 529 PPFD and the new light is 740 PPFD,if your growing tall dense plants then you might want that 1000 PPFD or more.
 
ttystikk

ttystikk

Well-Known Member
captainmorgan said:
I haven't tried to see how close they can go because of the lights design,the sweet spot is probably 8" to 12" for my set up.



Veg + Bloom and cal/mag at 500 to 600 ppm for the strains I'm running.



GPW is what I use as a gage for my own grows and I think my set up is nearing a max output but I'll see what this new light is capable of in the next couple grows. I'm one that believes PPFD should be matched to your grow style and you don't need 1000 PPFD on a scrog. I can get in the 2 GPW range with 529 PPFD and the new light is 740 PPFD,if your growing tall dense plants then you might want that 1000 PPFD or more.
Click to expand...
Very nice, indeed. I like the frost development at this stage, too. I'm trying for good coverage at about 24" average distance, but my array is also pretty big. I've been wondering about lens choices but I think I'll just have to wait and watch.

I'm running over half again your nutrient strength. If you're on the ppm = EC x 500 scale, then you're running 1.0-1.2 EC. I run up to 2.0 under 860W CDM light, I'm wondering if bumping your feed might be beneficial under more intense light. Or, if the reverse is true, since I'm running less than 500 PPfd at the moment.
 
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captainmorgan

captainmorgan

Well-Known Member
ttystikk said:
I'm running offer half again your nutrient strength. If you're on the ppm = EC x 500 scale, then you're running 1.0-1.2 EC. I run up to 2.0 under 860W CDM light, I'm wondering if bumping your feed might be beneficial under more intense light. Or, if the reverse is true, since I'm running less than 500 PPfd at the moment.
Click to expand...
It's completely strain dependent,I've run strains that could take 2 EC or higher. GG#4 is a light feeder and going over 550 ppm will result in leaf burn and actually hurt your yield if you push her hard. Everyone that I have given the Glue to has ignored my advise and over fed her on the first run or two but they eventually come around.
 
ttystikk

ttystikk

Well-Known Member
That's a dry nutrient mix, right? Is it for hydroponics or soil media?

I'm using dry nutrients in RDWC, but I hear and see lots of good things with the veg+bloom lineup.
 
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