I used to think 6500 K lamps were too blue, but now they look about right to my eyes.
If each of your lamps has an individually corded ballast, you can put each one on a separate timer and have a multi lamp midday blast by overlapping the times. Saves the daily hours on each lamp tube and they will last longer.
I totally forgot to mention what I run on my tanks for lights. on my 20 long I run a 10k 420nm (actinic) combo I think it looks great honestly.
on my 125g I run 3 54w x 67k N.O. fluorescent (over-driven) and one actinic 110w vho. (icecap 660-009 ballast)
my 125g is 24 inches from soil to surface. this combination allows me to easily push photosynthetic light all the way down to the substrate. at about 2.17 wpg.
"[Wabi-sabi] nurtures all that is authentic by acknowledging three simple realities: nothing lasts, nothing is finished, and nothing is perfect." -original author unknown-
125g marine reef tank, 6 gallon fluval edge minimalist aquascape (in progress), 1 gallon aqueon evo 2 betta tank.
After reading this thread I went out and changed the lights on my 25g to 6700k and 10000k, the combination of the two makes a really nice bright ( but not overpowering) light, it also makes the greens of my swords appear much more vibrant.