What size tank does an adult brazilian rainbow boa need? I know it's suggested to use a rubbermaid bin or custom enclousure for humidity issues but I want it to look nice and I can't afford a custom enclousure, so i will probably get one with at least a half glass lid. I'm planning on getting two babys and giving them each thier own 20 gallon long to start. once they get about 2 and a half or 3 feet long they will be moved up to an "adult size" tank. If the enclosure is too big will that stress them out?