I have a pond in my backyard which we put in late last summer and inhabited with several koi and goldfish. They seemed to do well all winter and startrf eating the wheat germ pellets early this spring but for about the past month they have stopped eating. We can still see them but they refuse to eat. We tested the water ph in case there was an imbalance making them ill but everything was normal. Does anybody know what could be wrong and if they are sick how do we determine and treat? Thanks so much in advance!