First off use what ever water you want in most cases it is going to be setting in the tank a "LONG" time before it is ever used. I have had mine setup for around a month and a half and still havent got to use it :nope: . That said I would search for a post by beth about QT tanks it is really good and will get you off to a good start I read it and followed to a T and my tank cycled step by step with my main tank.