Lol, No it will get to big and will need to be transplanted to a bigger pot. And by that I mean If you keep it there forever it could get root bound and die. The roots dont stay 3 inches forever. A plant grows just like a person. If you stayed in a small box would that stop you from growing? Get some lowriders. A plant has to get big if you want some nice buds. Inless your looking to get a tiny bit then go ahead and take shitty care of your plant. I'm not trying to sound like a asshole I was just warning you about root bound. Try a outdoor grow next year. Its to late in the year to start a grow (Most places). And if you have it inside with no lights how will that work out? Ouside yeilds more btw