I was given some GSC x Royal Kush from a friend that tests genetics that wasn't going to pop them. I germinated them in tap water. A few sank immediately but most sat on the surface for at least 24 hours. After the first 24 hours I tapped the seeds lightly and they sank down. After another 48 hours I chose the 3 best looking ones and planted them in small glass pots to start them.