I have had my 5 inch black rhom in my 20g tall for three weeks. He never comes out of the hiding cave I put in the tank. I mean never. I find fish bodies and turds from him in the cave so he must come out at night. Is this normal and when if ever will he come out of the cave? The lights are on for mybe 8 hours and I have the light wrapped with electrical tape to dim it. I am thinking about getting him a bigger tank but if he just sits in a cave all day, what would be the point? Thanks for the input.