Chris, welcome to the boards(forums) and the world of CEN ownership..

5 hours should be enough to get your engines started.

You really should not leaveyour fuel in any open container, the nitromethane will evaporate very fast and the alcohol will absorb moisture. Your fuel shouls always be kept in an airtight container in a cool dry location..

Again Welcome, And feel free to use the search feature to answer all your questions. if the search does not get you results then ask!!