Thanks for all the encouragement, fellas!
So far, this system has been completely passive. Because it's under a clear plastic lid, I haven't even needed to add water. Since "planting" about 10 days ago, this thinning operation has been my only intervention. I had read that I needed to be super careful with the tweezers. So much so that I actually started the process using two q-tips like chopsticks. That didn't last long, though.
To answer some previous questions: The 'hydroponic' kit is new, single-use peet cubes. I assume they're sterile, but I don't know for sure. So hopefully I won't have any disease issues.
There are a few cells of Rustica, two kinds of Virgina, one Burley, and a coupla Semois. Those are the seeds Jitter sent.
Cosmic, Thanks for the spotlight, I suppose. Although I will continue to keep your previous year's grow-logs bookmarked for reference. Thanks for having done that, it was absolutely responsible for inspiring me to undertake this project.