Hello halfway,
Sounds like the plants are doing good. I'm not surprised at the basil, the basil that I grew got about 1 foot tall and 1 foot wide before I pulled the plug on it because I wasn't able to keep the
nutrient/water temperature under control any more, so I'm not sure how big it would have gotten. 68 degrees is a great temp for growing lettuce. I wish I had a basement where I could grow year round lettuce greens like that.
Just wondering, how deep is the water culture systems for the lettuce that your building planed to be. Mine did great in a regular water culture system, with the water only being 3-4 inches deep. Although the deeper it is, the more of what I call buffer water (
nutrients) there will be. That could allow for longer intervals between nutrient changes, provided you keep them fresh by not allowing to much algae and other things like unwanted pathogens to grow in it. Good aeration of the water, water circulation, blocking light and keeping the water in the right temperature range will help a lot in keeping them fresh as long as possible. In a water culture system (deep or not) when there's no water
pump circulating water, an air pump and bubbles from air stones keep the water moving (circulating), as well as aerate the water. So the more bubbles, the more movement the better. Especially when trying to keep them fresh for longer periods. But for me, I don't think there's a need, or even much benefit for it being deep just for lettuce.