I have a group of 3 4" gulpers. In a 40 breeder all to them. They seem to have no appetite. Ive had them a month now they eat live. But tried getting them on shrimp. I was told thats,what they were eating. The big one ate a small piece of shrimp week ago but thats it. I try putting it in front of then.turning lights out. No luck. Ph 6.8. Ammonia 0. Added neutral regulator to soften water for them. Temp at 80.