Gulper won't eat

[Skyeboy]

Ive had this gulper cat for a,week now and he wint eat anything. Previous owner had him on shrimp and live. He wont even look at ether. Water param are good. Ph at 6.8 and temp at 80. Hes 4-5" in a 40 breeder

 

[thebiggerthebetter]

He might simply be still adjusting.

What is ammonia, nitrite and nitrate in ppm and how are they measured?

What is water hardness KH and GH? Or at least qualitatively - very hard, hard, moderately hard, medium, moderately soft, soft, very soft?

Is aeration adequate?

What's the lighting like?

Could it be bullied?

Does is have a place to hide or wedge into?