Our vacation went well, and we are back in town. No fish casualties. The corn has grown literally another foot and has lots of tassles on top, but no ears forming. :(
The squash and pumpkins are doing really well, with lots of flowers showing. The tomatoes are stalled, because the corn is taking all the light.
I'm going to give the corn another couple of weeks and if it remains barren I'll chop it and give the tomatoes a chance.
Observation: Between Gravel Flood and Drain vs. DWC, Flood and drain in the gravel is remarkably more productive. Uncontrolled experiment, disclaimer applies.