Fact- you're wrong. Plants only need darkness when your trying to flowering them. If your just vegging its perfectly fine to keep the lights on 24/0 or 18/0. People have tried both and the results are not dramatically different either way.
A few if the downsides people have mentioned are excess heat build up, also your electricity bill will be much higher. Maybe not so much with flouros, but still more.
Fact- you're wrong. Plants only need darkness when your trying to flowering them. If your just vegging its perfectly fine to keep the lights on 24/0 or 18/0. People have tried both and the results are not dramatically different either way.
Once again, no. contrary to popular belief, marijuana doesn't need rest period to perform photosynthesis properly. I can't speak for other varieties of plants, but marijuana is very light demanding and does just fine with no dark period.
Either way, I use 18/6 because it would get to hot in my grow room if I had the lights on all day. plus its a little cheaper in the long run.