You can grow a plant with just feeding it water, but the results ain't gonna be that great. Here is a C-13 haze I gre just fed water, not one nutrient added. It was just in regular soil which of course will always have some sort of fertilization. Water however as we know contains many of the eswsential nutrients that plants need, and air also provide a certain amount of available Nitrogen that can be used.
This was a couple of years back, the buds ended up quite light but tasted great. This was done with normal sunlight as well.
HeadsUp: Regarding getting seeds in every grow. I think if you are working with fem'd seeds then there certainly is a tendency towards seeding itself. Often you don't see the mail flower because the bud has literally grown round it, another reason why you only get a couple of seeds. I think as well, the more you push your plant, the more likely it is to self itself (and pushing can also mean maximising yield by training, stressing, etc IMO.
Have a nice weekend 600 Watters.
Peace, DST