Looking really good for 17 days. This is insteresting cause I happen to have two photosensitive Ultimates growing under one HS1 with DWC. They are almost the same age. I believe they are 19 days to be exact since I started to seeds on the beginning of this month and it took them couple of days to pop.
Good luck with the grow! You have jst ridiculous awesome amount of light power. I will be following this one with interest.