COB color and lens vs reflector questions

[Greenfing]

Im planning my DIY veg and bloom cob build for scrogging and I need some input from you guys.

The lenses will protect the COBs from dust and damage, but it also remove some of the light and also focus the light to a smaller footprint, will that give me better penetration? is there any benefits other than protecting the COB?

Im thinking ill use the CREE CXB3590 COB, all 3500k for full cycle? 50/50 3500K + 5000k? Why dont i find people using the 2700k for veg? 50/50 2700k + 6500K? Should I add some full spectrum COBs? UVB? UV? IR? Red? Blue? I would love if someone could give me some pointers here

 

[greensunshine]

2700K works great for veg. You'll get faster and larger growth than 6500K. You'll be able to veg, bloom, do everything with that.

I might mix 2700K and 5000K together 50/50 and you'll have a killer setup.

Blue inhibits plant growth so if you're looking for smaller plants, throw in some 6500K. Otherwise, you're on the right path. Keep it simple and you'll get fantastic results. LMK if you have more q's I'll help out.

 

[Scientific]

Blue inhibits plant growth so if you're looking for smaller plants, throw in some 6500K.

With respect, 6500 kelvin light is commonly called "daylight" or "day white." It's not as warm as 2700K light, but plants can and do thrive under nothing but 6500K light (I have grown under nothing but 6500K), in much the same way that they grow and thrive under natural daylight. If the claim is that 6500K light inhibits plant growth, I think that's highly misleading.

 

[SlantEye]

In for a good read

 

[Scientific]

Why dont i find people using the 2700k for veg?

At the home center, 2700K light bulbs are sold as "warm white." Usually the warmer (i.e. redder) end of the spectrum is used more at bloom than for veg. But as the earlier poster said, 2700K works for veg. Having lots of light trumps the fine points of exactly where in the spectrum the light falls.

 

[Icemud]

Im planning my DIY veg and bloom cob build for scrogging and I need some input from you guys.

The lenses will protect the COBs from dust and damage, but it also remove some of the light and also focus the light to a smaller footprint, will that give me better penetration? is there any benefits other than protecting the COB?

Im thinking ill use the CREE CXB3590 COB, all 3500k for full cycle? 50/50 3500K + 5000k? Why dont i find people using the 2700k for veg? 50/50 2700k + 6500K? Should I add some full spectrum COBs? UVB? UV? IR? Red? Blue? I would love if someone could give me some pointers here

I would actually recommend 2700k for the full cycle, veg and bloom. I have run controlled side by sides and the lower color temp will do better for both cycles than the higher (bluer) color temp.

The reasons are that lower (redder) color temps stack mor photons in the orange/red region which has some of the highest absorption percentage of the PAR spectrum where 580-620nm is almost 95-98% absorbed. Higher color temps in the blue end (6500k) actually have more photons in the blue region which is very energy heavy photons, blue photons pack much more energy than red so the plants have to use more energy to produce anthocyanins and other protective pigments which also in some studies of other plant species heavy blue light over 25% has shown decreases in photosynthetic activity.

Both will grow plants fine, and the difference will be negligible but there would be a difference as I have experienced in controlled environment testing.

 

[Scientific]

Thanks for sharing your experience, Icemud, especially the controlled, side-by-side info. That kind of information is hard to come by so really helpful!

 

[Greenfing]

Thanks for your answers
What about lens vs. reflectors? Whats the pros and cons? im kind of leaning toward lenses, as it protects the COB.

 

[Scientific]

Thanks for your answers
What about lens vs. reflectors? Whats the pros and cons? im kind of leaning toward lenses, as it protects the COB.

You mentioned the lens absorbing or blocking (or whatever) light. I don't think that's going to be significant effect. Focusing the beam is another matter--could be good, could be bad, depending on what you want.

Just my two cents...

 

[LedTestLab]

Thanks for your answers
What about lens vs. reflectors? Whats the pros and cons? im kind of leaning toward lenses, as it protects the COB.

Reflector is nice because you got all the light from LED chip .. BUT reflector dont protect chip surface who is made of silicone and all small dust will stick to the surface. And thats very important to chips lifetime. For example if Cree write that they chips lifetime is 50,000 h then with no protection you reduce lifetime about 30-40%. Lens reduces light efficiency something about from 5-25%..depends from lens manufacturer. Chinese lens for 10 $ reduce something about 20-25 % light output.
For example Citizen clu058 - With reflector 15800 lm. With German lens same chip make 15320 lm. And same chip with chinese lens do 11796 lm.

 

[Greenfing]

Do I want the glass or Silicone lenses for my CXB3590?

 

[LedTestLab]

Do I want the glass or Silicone lenses for my CXB3590?

Depends of manufacturer. I will suggest glass.. Silicone as I know has a very small beam ankle. If you are ok with 30-60 degree ankle then silicone is nor so bad. We use silicone lenses for sport arena lights. This example below has a 30 degree. Silicone lense. But for grow I will suggest glass..

 

[Greenfing]

im thinking to get the Kingbrite KB-HB100-80 glasses, is there better alternatives?

 

[LedTestLab]

im thinking to get the Kingbrite KB-HB100-80 glasses, is there better alternatives?

KB-HB100-80 is not bad. Price is something about 10 us but your light will decrese something about 15-25 %.. Sometimes its 15 % and sometimes its 25%... Its china my friend. Also if you buy some COB's in china then be ready for some suprise. Of course sometimes everything is ok and there is no problems. You never know.

About those kingbrite glases, yes you can use them, they are nice in this price categorie and loosing lumens its nothing if you run nice COB's...run them at 100W and you will get 80W power in lumens.

 

[Greenfing]

KB-HB100-80 is not bad. Price is something about 10 us but your light will decrese something about 15-25 %.. Sometimes its 15 % and sometimes its 25%... Its china my friend. Also if you buy some COB's in china then be ready for some suprise. Of course sometimes everything is ok and there is no problems. You never know.

About those kingbrite glases, yes you can use them, they are nice in this price categorie and loosing lumens its nothing if you run nice COB's...run them at 100W and you will get 80W power in lumens.

Can you point me in the direction of a site that sells better lenses?
Should I expect issues when ordering Original Crees from Kingbrigte?

 

[LedTestLab]

Can you point me in the direction of a site that sells better lenses?
Should I expect issues when ordering Original Crees from Kingbrigte?

We made some project with cree cxb3590, and 3 of 10 COB's was with different power with same driver. Little bit less lumens. That was the last time I work with them.
Im not sure that I can put some link or company name here. I already have 1 warning. You have google... nice lens light transmittance is about 92-98%...

 

[Greenfing]

Hi,

I found some producers, Fraen, Auer Lighting, Khatod, LEDiL, Carclo Optics.
What about using one of the reflectors with flat glass covers like khatods LYRA Reflectors with their 2mm glass covers?

 

[Greenfing]

I just ordered two sets of Cree cxb3590, 4pce 3500K DB bin and 4pce cxb3590 3000K CD bin that I will run at total 400W. (the 2700K was out of stock) Ordered the KB lenses for all of them.

Any comments about my placement of the cobs?

 

[Scientific]

Any comments about my placement of the cobs?

I'll bet you could get into some detailed measurements very sophisticated mathematical analysis to try to get the light levels to be as even as possible (which seems like what you'd be shooting for). But just eyeballing it, your diagram looks good to me! (Though it would be interesting to get under the lights with a meter to optimize their placement.)

 

[Chris Scorpio]

I just ordered two sets of Cree cxb3590, 4pce 3500K DB bin and 4pce cxb3590 3000K CD bin that I will run at total 400W. (the 2700K was out of stock) Ordered the KB lenses for all of them.

Any comments about my placement of the cobs?

How much is that gonna cost when done, minus the HPS

Keep debating on building a COB setup, I have WAYYYYYY to much free time....ol