i have installed lutron ballasts and controls, for larger installations using t8's (16 cct controller with 88 ballasts plus multiple (8?) incandescent circuits (potlights, accent lighting, track lighting etc), 2 full function remotes plus 2 additional 2 scene remotes at the doorways). the installation was later connected to the a/v computer software.
they work very well, dimming capability is very good, and they will start very cleanly on the lowest setting, around 3%. i'm not sure if they have a small computer control like the one PJAN is using, but i would say check out www.lutron.com
and browse. the 'tu-wire' system is the one i'm familiar with. ballasts are very easy to wire. the 24 hour hotline has some very knowledgable people working the phones. there are simply 2 wires, 1 black, 1 white from the control to the ballast, which wires exactly the same as an ordinary electronic ballast.
i have installed the GRAFIK Eye 4000 series and also the 2000 series. in the 2000 series, there is an upgrade to allow for dimming below 10%, i think down to 3%. there is a suffix on the part number to identfy the upgrade but cannot remember what it is. they'll be able to tell you. personally i doubt that you'd need this option on a tank, but hey, if you are going to spend the bucks why not have all the bells and whistles. to allow 6 lamps each on it's own zone, 7 wires are needed plus ground (6 dimmed hots, 1 neutral i ground) from the control to the tank hood. check to see if there are timers that can be connected or programmed into the 2000 series, not sure on that. i believe that there is a separate programmer required to allow for this. this stuff changes all the time.
the only thing i'd say is to ensure that the wiring from the control to the lights is well shielded and run apart from other electricity. things can be erratic if there is too much interference with other sources of electricity ime.
the instructions say you need to 'burn in' the lamps which if i remember means to run them continuously for 2 days to burn the phosphors to the inside of the lamps properly. not sure what the difference is, i just did what they said to do.
this stuff is still pretty expensive.