I'm not running DWC's in each container...
What's going to happen is that water will stay in an external reservoir. From there it will be pumped to a drip ring that will drip down, along the roots, to the bottom of the bucket, where it will then drain out, back into the reservoir...from there, the process will repeat itself, so if I ever needed to change the water, I only have to drain the reservoir that actually holds my water, not the buckets that hold my roots...because except for the little bit of water there is that's stuck on the roots and at the bottom of the bucket, there's practically no water in there to change out, and whatever is stuck in the bucket while I'm changing out my water will only get flushed out when the new water is cycled through the system.