Which kind of tubes do you have - and in what order are they placed?
I have the iQuatics 4 tube unit on my Vision 180. I bought it with 4 off of their tropical tubes in 2016. I thought tank looked "pinkish" so I replaced two of the tubes with 2 off Juwel HiLite day tubes, these being more white (8000K). Addition of these tubes certainly makes the green of the plants stand out.
I have just recently changed the tubes (yes they has install date of Jan 2016), they were slightly dimmer but mainly I have suffered complete tube failures, tube just stops (or sometimes doesn't come on 100% of the time). The Juwel tubes did not last as long as the iQuatics ones. Some of the failures were my fault as I let the plants grow out the water and they touch the tubes and cause crazing of the glass and eventual tube failure.
I run 2 tubes 5pm to 5:30pm, 4 tubes 5:30pm to 10:30pm and two tubes 10:30pm to 11pm. I use a PLC controller to control the lights (and tank) and it cycles which "two tubes" to use, so as to wear out the tubes evenly (probably make no difference, but did it anyway). I have tube 1 Juwel HiLite at the back, then tube 2 iQuatics tropical, tube 3 HiLite and tube 4 iQuatics. Tubes 1 & 3 are on one plug and 2 & 4 on the other plug.
The original MK 1 iQuatics units, you assembled the two tubes into the holders and plugged the assembly into the center bar. Mine suffered dodgy contacts, but got sorted by iQuatics. The MKII the tube holders are fixed (and sealed) to the center bar, no dodgy contacts, a much superior system.
I have reflectors as well. They are aluminium holder that holds a reflective plastic strip. I have changes these strips a couple of times as after a couple of years looses its reflectivity.
