I also use a water setup, but my filter is soooo good at filtering I almost can't really tell when she goes lol. I shelled out money for a fluval 205, and the thing is a beast! Sometimes I see it but other times no. I would think after a week of digestion they would be good to go again, but I was just wondering if there we're known accurate time frames. Just curious but how did you createyour water setup for them?