You know, if you want the reservoir's to auto-refill themselves when they start to get low, look into a dishwasher. They have an electrically controlled water valve in them, supply power to the valve and it opens.. In comes water.. Pretty simple, you'd just need to have one sensor at the level where you want to add water, and another sensor at the level where the water is high enough to know to close the valve..

Oh, and you'd need to plumb some water from your house's plumbing over to the computer. heh..

Nice review, btw..