I'm growing nine plants under one 600w HPS, two different strains, all from seed. They're in their fourth week of vegetative under 18 hours of light, and they've begun to show signs of sex. Is this possible? I'm sure about at least a few females, but it's the male that I'm not 100% sure about. There are, what look like, sacks forming at two of the nodes, but they've been there for a couple of days with no major change? Any help would be welcome.