its been over a week, they come out when I present the cut up fish, (I use tilapia fillet, they usually go nuts for it) but they look at it and turn away. and then I have to throw it out after it goes bad,

I know they can brumate when the temperature goes down but the room where they are in is temperature controlled and they have both heating pads and full spectrum uv lighting to self regulate. I'm wondering if they might need to be fed something else. They used to take food every 2 to 3 days in the form of 3 or 4 bite sized chunks of fish.

If brumation is the key, how exactly should I go about that? I think the shed would be way too cold, and I think the basement might be too warm, (I live in eastern Massachusetts near Boston.) I have a smaller 10 gallon tank if that helps, I keep them in a 40 gallon.