I read in the book that to make them you have to put a potato peel in a cup filled with water. The water will be clear but some time it is going to turn cloudy and then it will turn clear again. And as soon as it turns clear you can pour some of that water in the tank and fish will eat it even though you might not see them!
Try it if you want! but i have never tried that myself!!! i don't know if it works!
