Controlling Mars Aqua lights should be pretty easy using Apex. I think Apex supports LED dimming via 0-10v analog signal. If so, that's similar to the way the Mars Aqua light are already controlled by the dimmer knob. If the knob pcb looks like the one in the thread Ranjib linked, then I think you're good to go.
Let me know, and I can probably help you get it connected.