(fallen london stamps by update: I gave the two plants that were showing signs of deficiency some tap water since our water is semi-hard. the next day both of them put out flower buds???
I trimmed those off and put the sprigs into water to propagate, but I'm just pondering like... were those specific two plants deficient because they were trying to bolt, or the other way around? it can be so hard to tell with plants and I haven't had much luck finding papers on the roles of calcium/magnesium in basil flowering specifically
on the upside, no more leaves seem to be getting scrungled up, so I'm hoping that my guess was right about the cause and the fix. this issue first showed in my lone potted plant (which isn't exposed to tap water) and only showed in the other, semi-hydro plant after I began flushing my semi-hydro plants once a week instead of twice. (I run them under tap water, so a good amount of it ends up accumulating on the orbs + roots and dripping into the nutrient water later.) I was curious about why it didn't show in the other semi-hydro plants, but after seeing those two try to flower I might have part of an answer. or maybe it's all coincidence. who knows