So we have our guy set up in a temporary enclosure, and it's only able to maintain a steady day and night temperature of around 87 degrees. for some reason his new basking lamp just isn't putting off the kind of heat we were hoping for. He's in a 60 gallon tub (high sides) which is about 18 inches by 48 inches. he has a food dish, a water dish, hide, CHE, heat lamp, and a UV lamp. He's on orchid bark. We have the top partially covered with a plastic lid to try to help retain heat, what else can we do, or does that sound alright?