Since my last update, we have harvested lettuce for salads or sandwiches every other day. That amounts to 2 large salads worth of growth in just 48 hours.
I have added about 2 gallons of plain water to keep the reservoir level stable, but have added NO additional nutrients since the 21st of November. PH is staying in check as well. This again shows how little maintenance this system requires.
The basil is beginning to shows some sign of mineral defficiency, but it is a more demanding plant than the lettuce. The signs are minimal, but I am watching closely for the rates of change and hoping to squeeze another 7-10 days from the current nutrient batch.