Some new aquaponic fish waste Tip: problem of : what is the ball as fish waste ?Our fish were swimming about and this large brown issue hanging under the belly, can anybody let me know if their waste or was it an egg? ! Totally confused Aid Greatest answer: response of Plesner K. eggs are white or extremely light gray. Your waste is grayish or brownish, depending on their diet plan. Sounds perfectly standard. Add your personal answer in the comments!