It's been a bit since I posted any progress, because basically these plants have been serving me my ego, thinly sliced and in its own juices.
Once I repotted them, the "hangdog" condition didn't change, and at once there developed yellow/rusty patches on the main fan leaves.
I got two tips from other growers regarding what could cause this:
1) thrips
2) pH
The thrips thing is fascinating because these bugs are so tiny that they can be missed even at 20X. So I got some "Safer" soap and have given the plants three thorough sprayings-down.
Here are the plants as of Monday the 3rd. Here is one of the Healthy Sisters, showing yellowing ... and those mauvey-gray patches on the big fan leaf.
The other Sister looked no better off.
So I essentially ignored the plants for a few days, while exploring the pH side of the equation.
When I repotted them, I noticed that the pH of my last few ml of nute read
four point six on my pH meter! I'd mixed that batch to 5.57 ... and had no idea how the pH went so far down.
The previous day I'd mixed a pot of nute to 790 ppm and pH 5.5. I rechecked it, and it had gone into the fours as well!!!!! I still had two liters of that left, and noticed that within a day of mixing, it became cloudy, and the pH descended all the way to 4.38. That's pretty danged sour.
I also mixed a fresh batch of 780 ppm at five point six. I was careful to not contaminate this (I think the bugs came from a month-old bucket of RO water. I washed the bucket with soap and ran fresh RO water into it.) and over the past week, its pH has been stable. I've just poured it into the contaminated Erlenmeyer in which i ran my microbiology "experiment".
Back to the sour batch ... two days ago the pH had risen to 4.8x, and today it read five point eight ... slightly sweeter than start. The brew was cloudy with tatters of bacterial scum ... I'm guessing they ran out of eats, died and returned their pilfered ions back to the solution.
Figuring that my pots were similarly inoculated ... and the plants survived, I shrugged and watered with this.
Here are the two Healthy Sisters ... their skirts look lousy but the shoulders/tops are thriving. After watering with the "recovered" nute, the first one's runoff was 810 ppm and pH 6.15. So for now I am calling the pH situation "provisionally settled" but am keeping a sharp eye on feed pH.
Here's Quasimodo, looking leggy and a bit Gimpy.
The Gimp herself. Those leaves look awful, but she's doing well otherwise, and the foliage on the branches looks rather more normal.
Here are the four under the Secret Sunlet. I have begun to LST them and am seriously considering whacking the twin tops and trying to clone them.
cn