Are those autos or photos? If they're autos , then, they really shoulda gotten a bit bigger in 6 days. Autos are just so sensitive the first rew weeks. But, I don't know shit about hydro so I'd probably stunt mine. If those are photos then you're great if you figured out your issue. I guess genetics matter too. If you're running some people's autos then you might have 6 weeks or more before flower starts. Every Mephisto plant I've ran has started flowering in under 5 weeks. Hey though, they say that taproot touching bottom is a big trigger for start of flower. A deep hydro setup might fix that. You'll nail it down eventually and be growing some big ass ladies.