Fantastic! Looking really good.
Have you looked into topping auto's? I'm having a huge issue with height with my current grow. I'm kind of going backwards here... Never grown seriously with HPS, always used LED. This time around I'm using the HPS and have a crispy top, ran out of room. Looking into topping my next plant but can't find any serious/real life examples.
You will find that with your DWC setup that the plant will grow towards the max height end of the strain description. DWC makes for a smaller root system that isn't concerned at all with reservoir size (unlike soil pots). Thinking this might help you out as well. Hopefully you can find more info than me. I even did a Google image search and just can't really find any definitive answers or pics.
Either way, great job so far!!!