Well, there's this..
http://shop.stevesleds.com/Aquarium-Controller-Interface-Harness-for-Steves-LEDs-Drivers-harness.htm">http://shop.stevesleds.com/Aquarium-Controller-Interface-Harness-for-Steves-LEDs-Drivers-harness.htm</a>
Converts 0-10v analog to a PWM signal...
Whether or not you'd be able to switch on and off fast enough, that's another question... But possibly.