Mokona about 13months old, and Trix is about 2yr old. I'm feeding how the Dane County Humane Society instructed, where I adopted them from. I have 1 of these for each of them. http://www.amazon.com/Ethical-3-Inch-Stoneware-Small-Animal/dp/B0002AS5QE
I fill it just about half full. Mokona chows hers overnight, and Trix, pecks at his over night and most of the day.