Dear PetFlora,
First of all ,we have to ask for an apology from guod,in case we 'hi-jacking' his thread...
Yes...
Grow results ,are the proofs...
(I think you have seen my thread ....
Astir Grow Led Panel Project ..)
We have to wait for another 4-5 weeks...
(Although I consider my current micro-grow a total failure...
I messed up with the non-ionic surfactant I use and probably ,the tap water(from my habitat) is
also a...serial plant-killer...)
Anyway...
Neutral whites have plenty of blue at 440-445 nm...(100% of relative power)
Also they have a relative power over 60% ,from 520-525 nm up to 640-645 nm...
With a 'mild' & 'flat' peak close to 580 nm,at approx 85% of relative power....
They lack in power over 650 nm...The relative power curve drops sharply over 655 nm..
From approx 50% Rel.Pow. to 20 % R.P a bit over 700 nm...
Well...Sure you can grow a wide range of higher plants with just only Neutrals...
But....
Do not expect really 'heavy' yields ..At least regarding mj...
(Perfect,though, for cucumbers,carrots and some 'greens' like cabbage & celery.)
If you want yields in flowers ,like on wild flowering weeds(=mj )..
You have to add to the spectrum a bit more power,from 610 nm up to 730-740 nm ...
( Like temperate/sub-tropical ,summer sunlight ..)
That means...Warm Whites..
Ask yourshelf...
If you had ,another kind of artificial lights...
CFLs or VHO FLs or MH+HPS+LPS.....
In what ratio ,you would have use them ,for efficient flowering ?
Approx 2: 1 (Power
Φ = Warm : cold/cool )...
The same goes with leds...
For sure Neutrals are the 'middle' way...
But they will,probably give you 'mediocre' yields..
Look this graph of spectral powers ( Cree leds ) ..
Warm whites ,are poor in blue...But...
They cover ,a really, wide wl range in amber/orange/red and far-red...
So ,for heavy flowering....Power
Φ(light flux)= 2:1 (warm : cool)
Where 'warm' is mainly warm whites with a bit of red 630...( approx. 3 :1 )
Whereas 'cool' is mainly neutral with cold whites .. ( ? : ? )
( this ratio is still under research.But for sure neutral is the bigger part..)
Unfortunately,the exact spectra that makes mj thrive,is yet to be discovered...
And I'm not referring to photosynthesis,only...
Some experiments,we do 'formally' -in university-with nettle (Urticaceae spp.) ,may shed light on that mystery ...
After all ,nettle is a very close relative to mj...
(Also,they share almost exact ,nutrient needs and natural habitats...)
Hope I helped a bit...