Originally Posted by
drainbamage
One thing that I try and point out to folks is that as much as the 6700's will grow your plants the best, if the ack's or 50/50's make you enjoy your tank more due to looks, you'll provide better maitenance to the tank. This means your tank will look a lot nicer than the yellow 6700k tank with plants growing galore but no inspiration on your part to keep things maintained.
Also, bulb location does matter to a small degree. If you've got the lower light stuff (like the crypts) near the front of the tank, and the higher light stuff (grassy stuff = valsineria usually) in the back, put the 6700's in the " back " of the fixture and the 50's up front. It'll give you the looks you like plus the plants will get more of the focus they need.
So what do you think so far of the combo you have running?