It's really a matter of personal taste. Some people like a very cool, "white"
light, others like a warmer tone. It sort of depends on what fish you're
keeping, too; red fish tend to look washed out in very white/blue light. OTOH,
blue fish like neon tetras will really glow.

Given the choice of 10,000K, 6,700K and 7,100K what combination should I
choose, should I mix the lights or match them?

I think most people would choose 6700K. It's a good spectrum for plants, and
pleasing to the eye. If you prefer a super-white looking light, you can go
with the 10,000K, but a lot of people find that's too white, giving everything
a washed-out look. (Personally, I like it. I find the 6700K a little yellow
looking. But I'm definitely in the minority.)




Leigh

http://www.fortunecity.com/lavender/halloween/881/