Cause my silver arrow would eat around like 5-6 sardines or fishes bought from the super market everyday before this happened. But I think hes just adapting to the water that has just been changed into the tank cause I raised it with a tiger oscar at first with like separators cause the oscar kept on attacking the arrow and also the oscar just ate food and then spat the food out which was VERY ANNOYING and I knew there was nothing wrong with the fish but he was making the conditions of the waters worse and more disgusting. So we moved the oscar to another tank and took off the divider and since the gross stuff from the oscars side (like the **** and the food he spat out) washed over to the arrows side, the water mixed together witch then became gross and caused my arrow to have a fungus infection on the eyes of it (but it was still eating with the infection and the disgusting water) and then I told my dad to do a big water change cause of the fungus that was growing on to the eye and we did change 3/4 of the tank water so the infection would wear off (which it did)
We did buy a pelco for both sides of the tank but they were small and the oscar just ate them both only leaving their heads...