So for the past two days, Donatello has finally started loving her red leaf lettuce. Last night, I gave her about 3/4 of a large piece of lettuce which she ate most of in the course of 2 hours. I also gave her 4 or 5 pellets. In her feeding dish with the lettuce, she had carrot, anacharais, and hornwort, but I don't think she ate any of that besides a couple of nibbles on the aquatic plants. When I got up this morning, I saw that she had pooped a lot/a little bit of the runs.
But just now when I looked at the water, I saw this:
The water looks like someone sprinkled fish food flakes all over the water besides that one huge chunk in the picture.
The picture is of the huge chunk and a couple of the little pieces in a cup.
What is this?! Should I be concerned?