I bought a 5" Niger cat from a LFS about 3-4months ago. I put it in the main tank but the other fish are too fast when it comes to feeding. So i put him in a 150 G sump. I have yet to see him eat since i got him and god know when was the last time he ate at the store. I tried everything from flakes, various pellets, shrimps, small pieces of fish fillet. I tried feeding when light are off also. Nothing seems to work. He is always motionless and look dead unless you poke him then he'll move. His belly is really sunken. Please help as he is one of my fav fish. Water parameters are as follow. 75-78 degree, no ammo, nitrate 30-40 ppm. Weekly WC of 30%.