Both previous posters are correct.
I DO have bad news for ya though... this weekend, the power at my place went out for 7 hours PLUS it flooded- over an inch of water on the floor- a waterfall when you opened the back door... good times.
Trust me your half hour light difference in veg isn't the worst thing that can happen
Just be certain that during flower, if you have a power outage, yank the plugs until you are certain the power is back on and going to STAY on, and adjust your timer to read the correct time before starting everything up again. More dark is FAR safer than more light!
stinkyattic Reviewed by stinkyattic on . Light Cycle Interuptions, Oh No! *help stinky* Today upon arriving home, I found my plants in the dark... the power must have gone out. This prompted some questions. 1. Just how bad are light cycle interruptions during the veg phase? Not nearly as bad as if occurred during flower? 2. If darkness occurs when the lights are supposed to be on, this is not nearly as bad as light interrupting the night, correct? If the power does go out, is it best to just turn it back on and the plants will just think a cloud passed overhead? 3. Rating: 5