1. there's some risk...adding light; one or two hours?...MIGHT?.. slow the flowering growth?...some strains?...MIGHT? want to go back to vegging?...(you know...growing without growing flowering buds).

2. adding dark time...is probably safer; especially..if you have strong HID lighting.

3. get a timer with your first paycheck...:thumbsup:...congrats: enjoy your grow.

4. Good Luck...imp: