From looking at the attitude seed bank on that strain... it says they are autoflowering. That means they will flower under whatever light schedule you give them. I have heard that 20/4 is best for autoflowering. I would keep going on your current light schedule and take them through their 8-9 weeks or whatever it said. Autoflowering means they completely skip the veg stage and go straight to flowering. So you cant really "veg" them. If you are on week 3 then expect them to keep growing but not too tall. Autoflowering strains are usually really small. Plus with a name like "Short Rider" id expect it to be short. Hope I could help!