Flowering with Cree bulbs

stardustsailor

Well-Known Member
1000 Watts of new green leds ...= ~ 200.000 lumens ... (output 300mW @350mA )

Are they enough to grow weed ?

It should be best way ,I think ....
Most efficient ....

~ 200 lumens / Watt ....

Cant these figures ,just ' lie ' ...

Can they ?

;-)
 

churchhaze

Well-Known Member
Lumens doesn't mean what people really think it does. There's a conversion scale called luminous efficacy which converts watts of electromagnetic radiation to our perception of how bright it is.

When I say watts, I don't mean the watts powering the lamp, but the watts of energy in light leaving the lamp. Luminous efficacy (measured in lumens per watt), peaks at around 555nm and tapers off on both ends of the visible spectrum.

This means 1W of 555nm light will be given a much higher lumen rating than 1W of say 660nm light, even though the power of light itself is the same. This is simply because we see 555nm light as significantly brighter than 660nm light. It sort of makes lumen ratings an unreliable measurement, especially for leds. This is also why it doesn't matter why 630nm leds are often brighter than 660nm. They may be brighter, but that doesn't mean they have more radiant flux.

In order to give a number for lumens, they have to do a complete spectral analysis of their lamp and run a computation against the luminous efficacy curve to get the lumen value, a single number to describe how bright the light is to us.

I guess if you're comparing leds with the same wavelength, having a higher lumen value does mean it's more efficient.

CIE_1931_Luminosity.jpg
 

stardustsailor

Well-Known Member
Lumens doesn't mean what people really think it does. There's a conversion scale called luminous efficacy which converts watts of electromagnetic radiation to our perception of how bright it is.

When I say watts, I don't mean the watts powering the lamp, but the watts of energy in light leaving the lamp. Luminous efficacy (measured in lumens per watt), peaks at around 555nm and tapers off on both ends of the visible spectrum.

This means 1W of 555nm light will be given a much higher lumen rating than 1W of say 660nm light, even though the power of light itself is the same. This is simply because we see 555nm light as significantly brighter than 660nm light. It sort of makes lumen ratings an unreliable measurement, especially for leds. This is also why it doesn't matter why 630nm leds are often brighter than 660nm. They may be brighter, but that doesn't mean they have more radiant flux.

In order to give a number for lumens, they have to do a complete spectral analysis of their lamp and run a computation against the luminous efficacy curve to get the lumen value, a single number to describe how bright the light is to us.

I guess if you're comparing leds with the same wavelength, having a higher lumen value does mean it's more efficient.

View attachment 2668349

W-The-F ,I can't express myself,so simply- like that ?
How stupid can I be ,eh ?
Seriously ....



Thank you ,so much ,brother !
 

pepperdust

Well-Known Member
with the height.. you can get them as close as there is no burn..

over at IC, many many who use whites with no bleaching very close, only thing is color LED they can bleach ( reds i think they were talking ) .. I have some 4.2 watt XM-L2 that don't seem to harm very very close
 

captainmorgan

Well-Known Member
with the height.. you can get them as close as there is no burn..

over at IC, many many who use whites with no bleaching very close, only thing is color LED they can bleach ( reds i think they were talking ) .. I have some 4.2 watt XM-L2 that don't seem to harm very very close
Yea,I have them 4" away right now with no signs of trouble.
 

PetFlora

Well-Known Member
^^Contact manufacturer

Oh, and great find on the Far Red lamp, good price, too!

Plus, it will fit between my 2 vanity fixtures
 

captainmorgan

Well-Known Member
Well because of my timer and heat trouble in the beginning this is really at the end of day 7. She's now 26" tall and the lights are within 4" with no signs of problems.
One of the Cree 5000k's died so I replaced it with a 2700k because they still have no 5000k in stock near me.
 

Attachments

caretak3r

Well-Known Member
I did a DIY far red flower initiator for about $25. 1W 730nm LEDs were $3.36 each so that's the key to how it would scale. Mine is about 6W:
IMG_20130528_074111_05232.jpg
 

caretak3r

Well-Known Member
merryday168 ebay seller- I ordered several different panels from her - she'll solder the LEDs for you and help you choose drivers, etc if you contact her. I had everything shipped DHL (about 1.4Kg for all the panels and drivers) for ~$30.
http://stores.ebay.com/merryday168
 

captainmorgan

Well-Known Member
Day 14,shes 31 inches now and buds all over. So she has grown 12" in 14 days and looks quite healthy.Most of the time her leaves are reaching for the lights which I've been keeping about 2 to 3 inches away but she has grown up to almost touch them at times with no signs of trouble.Shes a little droopy this morning because I let her dry out a bit to much,but shes perking up now that I gave her a drink.I'm not sure if the growth is normal for this strain because of two things,this is the first time I've grown LSD and my first ever run with super soil.So far shes looking good.Sorry about the quality of pics but only have a web cam or my crappy cell camera.
 

Attachments

captainmorgan

Well-Known Member
Day 21,35 inches tall and looking very healthy and starting to frost up a little.Trimmed up her bottom third and cut out some suckers and the stretch has slowed some.Running 13/11 with flower initiator and added 4 Cree 2700k in the back corners for side lighting and rotate the plant 1/2 turn each day.Not familiar with this LSD strain but it looks good so far and on schedule for 65 days.So I've got 188 watts of Cree bulbs going,152 watts of 2700k and 36 watts of 5000k covering around 6 sq ft.
 

Attachments

captainmorgan

Well-Known Member
Day 28,36" tall and she's almost doubled her height since going into flower.Looks like the stretch is over and the buds are starting to build nicely.Still on 13/11 and 188 watts with the flower initiator at lights out.Had to add some stakes and tie her up for support.Looks like I may have a mag def started on a few lower leaves (yellowing with green veins)so I gave her a epsom salt foliar and drench.Going to keep a close eye on her this week.
 

Attachments

PetFlora

Well-Known Member
NICE!

I ordered 4 @ 4ft iBright 23w tube leds (@ $35) uses 5050 Samsung diodes; my reasoning being consistent coverage over a broader area (no hot spots) should pay dividends

Will be adding them to my existing DIY light set up. Using the 2 CREEs below canopy thinking they should rock the lower buds


View attachment 2702751
 
Top