Blazinator,
4,300 is not lumens, I was referring to light temperature.
Globes produce light of different temperatures. Incandescent lights are typically down around the 3,000 K mark and so appear 'yellowy'. Unfortunately everything you light up underwater then looks 'yellowy', and can appear, 'dirty'.
LED's and HID's can be higher colour temperatures and so look 'whiter'. Lumens is one measure of brightness and, all things being equal, in HID's is predicated on the colour temperature. The most efficient brightness output comes from a HID globe of equivalent to the same temperature as light from the sun, around 4,300 K. The added advantage of this is that everything you light up underwater looks, 'real'. Higher colour temperatures start to look blue and even higher, eventually purple. The downside is that less lumens is produced the higher the globe temperature you use.
When buying or building a HID you should be able to choose the colour temeprature of the globe
With LEDs it is the same, although the choice of colour temperature is typical less. Choices such as, "cool white" and "warm white" refer to degrees Kelvin of the LED.
I've attached a picture of two 35W HID globes in MR16 size. The one on the left is 3,400K and so appears more "yellowy", than the one on the right which is 5,000K, more "white".
Hope this helps
Mac