Stephenj37826
Well-Known Member
I'm thinking we wont see the best numbers because the canopy isn't full. Still should be some quality product though.
CXB-8 Grow Journal
- Thread starter Stephenj37826
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- cxb-8 johnson grow lights
verticalgrow
Well-Known Member
ttystikk
Well-Known Member
Agreed. Should still be a decent test of the light. I'm liking the plant's response to the light; just like most pics I see of plants under CXB3590, they look really happy and show very little light or heat stress.
Stephenj37826
Well-Known Member
Yes plant response is something that everyone has noticed across the board. The 3000k cxa3070 lights are having great plant response/growth rates as well.
ttystikk
Well-Known Member
There's really two basic reasons I'm stepping up to COB LED; efficiency is one and dramatically better light distribution/lack of hotpots is the other.
I'm sooooo sick of my fucking heat lamps I could spit.
Stephenj37826
Well-Known Member
Damn bro still having problems?
And this is exactly what I was questioning you on. You no doubt built a seemingly good quality light, but packing all that light into such a small footprint is not efficient. With or without lenses, it still needs a larger footprint for all those. You can tell from your latest pictures that this is the case. You say you wont get the best numbers due to canopy not being full, but that seems like a direct response to your light.
Stephenj37826
Well-Known Member
The fixture is 25"X 25" the canopy isn't full do to a ph issue in veg and the loss of a couple plants. he lowered the light to cover the canopy that was left. the fixture is meant to be run @ 24" as you can see he is at about 14".
BTW that is the cxb-8 is 400 watts driven 440 watts total.
Also look at the picture does it look like a lack of light in the empty part of the canopy?
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Stephenj37826
Well-Known Member
Stephenj37826
Well-Known Member
Hey, no need to get defensive. Its an observation thats valid. 25"x25" fixture, with about 3" off the edge for each of your end cobs correct? So the center to center of the cobs is roughly ~19", leaving ~15" to each side of your cobs with no overlap. You are overlapping a ton in the center, with not much on the sides. In a 4'x4' footprint, this DOES matter. That is one of the benefits to LED (well, DIY) is spacing. The same reason people use 2x400w HPS instead of 1x1000w HPS and still get similiar results.
Again, this is a problem with most "commercial" lighting not just yours. You blame it on a PH issue which may be the case, but why the fuck would you document it then to tout your light? So you can have an excuse IF it does not live up to expectations? I would want the best possible grow if my light and reputation was on the line.
And who lowered the light canopy? I thought you were growing this? The canopy is not even due to the light. You have to run 24" to get a better light distribution, at the cost of less PAR. If you are doing some grows to document how well your light is doing, why would the light be lowered than optimal? Just some legitimate questions.
I know what your light SHOULD do. I know what my 11% less efficient light did without lenses @ a 16" height. Your plants look good no doubt, but you can even see in your pictures that the light isnt exactly reaching the outer ring as much as it should.
Again, this is a problem with most "commercial" lighting not just yours. You blame it on a PH issue which may be the case, but why the fuck would you document it then to tout your light? So you can have an excuse IF it does not live up to expectations? I would want the best possible grow if my light and reputation was on the line.
And who lowered the light canopy? I thought you were growing this? The canopy is not even due to the light. You have to run 24" to get a better light distribution, at the cost of less PAR. If you are doing some grows to document how well your light is doing, why would the light be lowered than optimal? Just some legitimate questions.
I know what your light SHOULD do. I know what my 11% less efficient light did without lenses @ a 16" height. Your plants look good no doubt, but you can even see in your pictures that the light isnt exactly reaching the outer ring as much as it should.
Stephenj37826
Well-Known Member
robincnnWell-Known Member
↑
I'm not sure if I understand what you mean. Could you be perhaps a little more graphic please and try me with a picture?
Example for 4x4
If we average all the numbers we get 572, which is wrong in my opinion.
The Green area is 1sqft. So multiply average PPF in this green area with 1 weighing coefficient.
The Blue area is 3 sqft. So multiply average PPF in this blue area with 3 weighing coefficient.
The Orange area is 5 sqft. So multiply average PPF in this orange area with 5 weighing coefficient.
The yellow area is 7 sqft. So multiply average PPF in this yellow area with 7 weighing coefficient.
Now add all and divide by total weighing coefficient (1+3+5+7= 16)
Why yellow 7sqft?
4x4sqft - 3*3sqft = 16-9=7
All formulas are in the attached excel
for Data1 column I will explain for row #1 (900+840)/2= 870
for Data2 column I will explain for row #1 (900+810)/2= 855
for Data1 column I will explain for row #2 (840+720)/2= 780
for Data2 column I will explain for row #2 (810+570)/2= 690
@guod
Let me know if you see anything wrong with this approach.
@Stephenj37826 Thanks for letting me use your data to explain this.
Attached Files:
a" style="margin: 0px; padding: 10px 10px 0px; overflow: hidden; zoom: 1; border-radius: 5px; background: url("styles/xpert/xenforo/gradients/category-23px-light.png") 50% 0% repeat-x rgb(255, 255, 255);">- PPFD example.zip
File size:
10.3 KB
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5
Oct 2, 2015Report
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Stephenj37826
Well-Known Member
This light isn't meant to be run so close and that is the growers decision not mine. Also I'm documenting it as is. I could have just waited to see and posted it only if it was great. That to me is not being transparent really. Like I said each person is entitled to their opinion for sure and in a multiply light setup this light will do just fine I'm sure. I'm happy with it and we have a couple 6 lighters going but I don't have direct access to the results but I'll find out sooner or later.
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ttystikk
Well-Known Member
New stuff is en route, but the old heat lamps are still the primary source.
Yes, still having problems with other equipment.
2cent
Well-Known Member
Love you no pun intended but this was on Facebook as I read this lol http://www.instructables.com/id/Make-your-own-cellphone-from-scratch/
ttystikk
Well-Known Member
Sure, I never said it couldn't be done- but how many people do you actually see doing it?
I appreciate you leaving it up to another grower. I did not realize that you werent growing. Maybe choose your grower a bit better, someone who can devote their attention to it and give your product the best possible shot.
And while I understand your light is not intended to be run at 14", even at 24" you are still not being as efficient as can be. Regardless, your lights look like quality builds and will serve their purpose well. Seems like you are selling a decent amount of them already and if people are happy, thats all that matters.
2cent
Well-Known Member
i know
just saw it funny that was there xD had to share it i agree tho i know many ppl that dont have the time or arnt very diy and when it comes to somthign liek this you hide, alot wil turn to buying it done, 
i couldnt even believe ti when i heard i could make one lol
WestDenverPioneer
Well-Known Member
It looks to be hot in the center. The pic of the canopy view from the side looks like a pyramid. The growth is not even.
If you're blaming the grower, then I'll wait to see another run with the light.
If you're blaming the grower, then I'll wait to see another run with the light.
Stephenj37826
Well-Known Member
He has the light lowered because the canopy isn't full. The light is designed to be run at 24" above the canopy. His next run will be documented as well. His first Grow since 2002 so not to bad really just not used to growing in a tent at all.