K=kelvin which is color temperature, spectrum is measured in nm=nanometers.
As for which K rating, its all up to whatever you wanna do. 6500K is the best for growing coral, but is not very aestitic. 10,000K is crisp white, 15,000K is blueish white, 20,000K is blue. _________ Got Questions? Need Answers?
"Believe those who are seeking the truth; doubt those who find it." Andre Gide  |