I just dealt with the same problem myself, I approached it in a different way though. Instead of wiring an extra plug for each switch, I spliced in timers in series for each circuit. This left only one plug for the entire ballast to plug in and left me with timer control of each lighting circuit independant from each other.
Here's the list of parts (from any hardware store): 16 gauge stranded wire(easier to work with in the small space), 6 wire nuts for 16 gauge wire, and 3 Intermatic wall switch timers.
WARNING - unplug the ballast box before doing any of this work.
First, prewire (for series as per the timer directions) and mount the timers in a seperate box. Be sure to label each set of wires for it's respective switch.
Second, unplug and open the ballast. Locate the white wire coming from the plug and follow it to the fuse. Coming out of the fuse will be two black wires.
Follow one, it will go to #9 on the terminal board. This will be the circuit for the MH, cut this wire (not too close to the terminal board) and splice in the timer using the wire nuts. One splice from the ballast box to the timer, another from the timer to the ballast box. It's just like repacing a wall switch.
Follow the other and you will come to a splice with two more wires.
Follow one of these to #5 on the terminal board. This is the circuit for the CF. Cut this wire and splice in the timer as above.
Follow the other one to #6 on the terminal board. This is for the moonlight. Again cut and splice in the timer as above.
You're now wired! Close up the box. I ran my wiring through the side vents of the case to prevent pinching or crimping any wires while closing up the box. This has been working very well for me and I hope it helps others.
Some things to note: I never saw any markings on the fixture or ballast for UL certification, so definitely have this plugged in to a GFI outlet. I chased each wire and drew out the schematic, but I'm afraid that I'm probably the only one that could decipher it. If anyone has any questions, feel free to ask and I'll answer the best I can.