Looks overwatered, soil mix seems to have no perlite. I can't see the leaf colour due to the light glare/angle so hard to tell nutrient state. It looks small for 3 weeks, and a bit drooped. Moar pics/info.
Your PANTS were on 12/12? Sadly I dont think they will flower... If on the other hand it's a pLant as dlftmyers said just get it back to the right schedule asap and try to stop that problem happening again.
slightly easier as you don't have to switch them to 12/12, but generally the quality of autos cannot compete with photoperiod strains due to being crossbred with ruderalis. If you're spending all this money on a hydro system and LED lights it seems silly to me to not go the last step and get...
18/6 from seed is fine. That's the vegatative phase. Switch to 12/12 for flowering once the plants reach 1/3 of your total grow area. CFL's are great for clones/seedlings but you'l probably want a HPS for flowering (way more buds). Your plan sounds great, lets have some pictures!
I found the ones for £15-20 are just as good as the ones for £100. The only difference is the reliability, the ones for 15£ will break in less than a year, where as the £100ones will last a few years.