Can you post up a picture of the enclosure? I have a 20g long too. I have a large rock hide on the warm side and a pvc pipe on the cool side. Water dish is in the center. He usually uses one or the other. Do you use a UTH or Lamp for heat? I use a UTH on the warm side for mine set to 90-93*. It warms the substrate and raises the ambient temp in his rock hide up but the ambient temp outside his hide is around 80-82*. He seems very content with this setup. Eats every week and does his normal roaming in the eveings. Every bp is a little different but they generally like to hide unless its too cool or too warm.