Added backup airpumps/stones to each bucket in case of motor failure(and thinking that increased bubbles could never hurt). I'm realizing that DWC is inherently risky, as loosing O2 content will start killing your plants immediately. NTM, I'm getting airpumps for $5 a piece.
Recirculating DWC has some distinct advantages in that regard, and I'm considering a modification of my system.