You realize if you can see them in the dark period they're getting light, which is an absolute no no. Two or more bad things can come of this. These are the biggest problems.
1) Your plant will revert back to vegetative state (ive never seen this but I heard of it)
2) Your plants will slow or completely stop produceing bud resulting in a delayed and weak yeild. When I say weak I mean from a weight point of view, the plant will never reach its peak if theres not 12 hours of complete darkness. I don't know how this will effect potency.
Once that light goes out it should be ignored the FULL 12 hours unless you hear somthing fall in there, or smell wires burning from to much humidity and high powered exhaust fan.
To be safe I run 12 hours light 12 hours 15 minutes of dark to account for the time for the HPS bulb to go completely out and any issues you may have sealing the room on the way out if its built on a budget.
This is just MY take on it. If anyone has anything to add or correct im not gonna be a dick about it. I just like to help.
