The color spectrum of the light si primarily what you're going to be concerned with.Spctrum is commonly measured as degrees Kelvin. Generaly speaking, the higher the color temperature, the bluer the light is. 6500K is pretty yellow light. 10,000K is brigt white, and 20,000K is pretty blue. Generaly speaking, reef lighting will fall between 10,000K and 20,000K. The exact color temperature is largely personal preference, with lighting clsser to 10,000K giving better growth, and 20,000K better coloration.
Lumens are a measure of percieved light intensity, and will vary depending on bulb type and wattage. Typicaly reefers are concerned only with color temperature and bulb wattage, although the efficiencies of a given bulb type and it's reflectors does come into play as well.
If you want to talk intensity, typicaly
PAR (photosyntheticaly available radiation)and PUR (photosyntheticaly USABLE radiation) are the figures we would be concerned with, and can be determined uing a PA meter, although
PAR values can be estimaed based ton the bulb type, wattage, manufacturer,
ballast type and reflector type.
Was there something specific you were wondering about?
