Ok, the babies are much better today.
So here's what happened IMO...
They developed what looked like a manganese problem during the first week with yellowing from the stem side of the leaf out toward the tip. Fert damage usually starts from the outside edges inward and the damaged areas can get a little "crisp", so this was weird as it's way too early for mineral issues. Figured it had to be fert cuz Dragons are N sensitive and after testing the ppm, it was at 200 and change when it should have been around 80 max. I had added no fert yet, but because I recycled the hydroton, leaching was the only possibility.
After changing (and chucking) the hydroton and completely flushing out the system, I replanted. Later the pH wouldn't balance. It kept diving from 6.0 to 5.3 or so over night. After that happening twice, I remembered reading that Dragons were calmag hogs and realized they were sucking up the base I had added when I overshot the mark with pH down on setup. Every time I added base..poof..gone in a day. I added 20 ml (for 9 gallons) of calmag and off they went! They're really cranking now! I'm going to be pre-loading calmag any time I do Dragons from now on.
As for the pH thing, I think I may use that as an indicator for when to start adding calmag BEFORE a plant shows sign of deficiency. Less stress that way. I use 20 ppm RO water, so no initial minerals in the water. Overshoot with pH down then balance with Up. If the pH starts nosediving, they're scrounging the base for calcium.
In a nutshell...