mshuangchao;5023816; said:I've switched back to using the local feeder fish, Cirrhinus molitorella. They are less than 4cm in length.
Wasn't sure what these were till I googled it, and realised it's a type of carp. I recently read that fishes in the carp family (Cyprinidae) contain Thiaminase. http://www.theaquariumwiki.com/Thiaminase
Which is why I've stopped getting him Silver Sharks as well. So you might wanna reduce the number of these you feed him.