I feel like I heard places in CO, WA, OR among others that sold most of their stash their first few days.. I can only imagine what it would be like ifor it was more widespread..
What is your current EC?? One major issue I had when I first started growing, was doing autos in hydro.. At the time, there weren't any lot of resources because I did a bit of a hybrid hydro grow..
Regardless, at the size that seedling is, you really don't NEED ferts or feed, and tap water will typically suffice.. Too high of an EC usually causes pH swings.. Too low can typically just stunt the plants..
Also, what kind of water are you using, RO, distilled, tap, rain, other?? Tap water, if from a public source, can have buffering/chelating capacities..
Lots involved in the run-of-the-mill hydro set up, and a lot that is either misunderstood or not known at all.. Once you get it figured out though, it's pretty damn easy to at least grow some buds..