Hey StanF:
I've been experimenting with how many pellets I've been feeding my fish, and the frequency. Since my last post, I started watching them eat from the top of the water, swim down and "chew", like you said and then go up for another mouthful, for a total of two mouthfulls, then I don't feed them any more pellets. For a few days following, that seemed to still result in a long hard poop trail. So I reduced their feeding to one mouthful, once a day, and that seemed to be the perfect amount for about three days. Then Carol (the smaller of the two) had a super long (4 inches!) white stringy poop trail, which I read was a sign of underfeeding. So that day I gave her two mouthfulls at her regular feeding, and continued that amount for two days, watching her every day. Then she produced another long hard poop. So the past three days I've gone back to one mouthful, and today she's got another long hard poop.
I can't seem to find a good balance, and I'm getting pretty frustrated! Maybe she's just a unique fish that has different poops than other fish?