You will most likely run into height issues without some form of training, topping, or both. I grow in soil, so I’m not familiar with hydroponics other than the basics. But besides the height of the plant itself and its container, you need some space between the lights and the canopy. What type of lighting are you using? You might be limited to using CFLs or LEDs in such a small space due to the heat others generate. Plus these can generally be ran closer to the canopy.
You should join the forum and tell us a little more about your setup. You’re in good hands…lots of knowledgeable, helpful folks here. Welcome!