R/O water is water you would buy from a water depot or Grocery store etc. If you just plan to use your tap water don't worry, you will be safe. The bulb will not burn them, a majority of people that keep these frogs use bulbs. A 60 watt bulb would be the most you would want to use and you would want something like a red bulb or even a ceramic heat emitter. Some people and sites would even say 50 watt is the highest you should use. The ones that could really burn them would be basking bulbs or something similar that you would use for bearded dragons.