nice description...it helps a lot and so few do it!

those plants look pretty large for a 2 gal pot. can you see any roots getting pushed out of drainage holes or on the surface? (just read your last line of descr...but still, some pots are treated so roots won't touch them).

have any 5 gal's around?

and if they were mine and within a month or so of harvest, i wouldn't be adding anything but pure water for the remainder of their lives...sounds like they've been getting plenty already.