Hello, I was wondering if anyone has experienced any bad effects using Tetrahymena as zfish fry food? I've tried to give some to 4-5 day old fry and have had them (fish) die on me. I'm not sure whether or not it's the Tetrahymena, though... In this fish disease book I have, it lists Tetrahymena as a disease (parasitic??). Any suggestions?? -Yiing Lin ylin at acpub.duke.edu