I use two Juwel HiLite Day and two equivalent to Juwel HiLite Colour on my Vision 180. The colour tube (6400K) by itself is too "red/pink" for my liking, makes plants look too dark but when mixed with the HiLite Day (8000K) I think the plants & tank looks OK. 8000K by itself can make the plants (& tank) look "washed out" & too white.
T5 tubes last for years (compared to T8 tubes), especially with Juwel electronic starters that don't use the heaters in end of the tubes. Ye Olde fluorescent tube starters used heaters either end to start the current flow, which is why you used to get blackened ends of tubes during their life (heater metal evaporating), 99.99% of tube failures was heater failure. Juwel electronic starter applies a 2000V pulse across the tube and does not use the heaters, thus T5 tubes will have a long long lifetime.
Here is graph of light output vs time for a T5 HO tube. So down to 90% level after over 15,000 hours, @ 8 hours per day is 5 years.
Here is my experience with Juwel HiLite Day T5 tubes,
Tube on right is 30 months old and one on left is 6 months old. Possible slight differences in brightness, but hardly significant.
This was Sept 2015 and these tubes are still going.
Actually not quite true, my plants grew and populated the reinforcing bar on my Juwel tank, I get nice carpet growing there. Unfortunately I let the growth touch a T5 tube (the new one
) and after a while the tube failed due to crazing of the glass where plants touched it. I now push/trim the plants away at each water change now.