I just bought my fixture for my tank. It is 48" long t5 8 lamp X 54W the fixture came with 6500k lamps... I am wondering after I am done with the lamps the fixtue comes with should I buy 6500k again or will 10k be better?
The colour temp of the lighting is really an aesthetic thing, 6500k is just a nice white light, but if you want to bring out the colours of the fish then you can easily change them for others if you wish. Plants are not overly fussy about the spectrum of the light, more so the amount.
BTW its got 8x54w lamps? That's loads! How many were you thinking of running at anyone time? Have you got a link to the place you got it from, I'd be interested to see the fixture!