Foil screwed up my last grow attempt...i'd only suggest using it when your plant is SCREAMING for light. Otherwise...avoid, as it can slowly, but surely, scorch your plant.

With seedlings...the lighting should always be 24/0, untill the plant begins vegetative growth. This is assuming you have a fairly weak flouro light (80 watts). If like me, your flouro is 150 watts...then cut down (a bit) on the lighting. As too much, can burn the living fuck out of your plant. A high wattage flouro should have a lighting sequence of 18/6. This will prevent your dirt from drying out too much, as well. As high watt lights, put out alot of heat.

Or if you want to use a convenient lighting sequence, keep the lights off untill it's dark outside. Then turn them on. Go to sleep. Wake up. Then turn them back off, when it's light outside. If it's sunny outside, then technically, that sort of is a 24/0 cycle. Depending on if your plants are getting that sunlight when it's daytime. =P