Soon to be owner of a new baby dragon. He will be in a 20 gallon long tank until he grows. I have a 50W halogen bulb for the basking side and I mounted a tube fixture under the hood on the other end of the tank. Should I use a 5.0 or a 10.0 reptisun tube because of the small tank size? I don’t want to give him too much uvb.
In a tank that size I'd get a 24'' T5 fixture and use a 5.0 (or Arcadia 6%) bulb in it for now. Set the main basking area about 6'' below the bulb and that should work pretty well. When you upgrade the tank you can move the fixture and just upgrade the bulb. The 10.0 (12%) version should sit about 12'' above the main basking area.