The potatoes will grow in the space below, and regrow after harvest if you remove the potatoes carefully without disturbing the roots. If the potato tubers get in the standing water they will rot or taste moldy. It might be good to build a tub grower which is deeper than the 1' in the tub systems. A single tub grower can produce 20 pounds of potatoes in a single growing season. They will be ready to begin picking when the blossoms start showing on the potato plant, and can be picked at any size.
Flavor seems slightly better when the potatoes are new or smaller.
Flavor and color and texture is more from the type of potato than any other aspect. A fresh potato raised on a trace nimeral supplement usually has very fine flavor and texture. Trace mineral supplements should be added to the water of the potato plants as they ripen. This can be from a mineral supplement from a health food store, and we are selling Equinox Master Formula for this purpose. Some of the flavor is apparently due to trace minerals.