It certainly isn't enough to sustain a single person but it's still nice to supplement your diet with fresh herbs and greens.

It's not viable for growing fruit or vegetables, though. That just doesn't make any sense economically.

We have a very similar hydroponic garden at our office and it's not a lot of work to maintain it. Basically adding a few buckets of water every week is enough. Every few months it needs an hour of maintenance, though (planting new seedlings or cuttings).

There are also organic hydroponic nutrients available. A dollar per day for nutrients is way too much if you're growing salad. Your basic plant food from the supermarket is a few bucks and lasts for months. You can spend as much money on expensive weed nutrients but that isn't necessary.

Hydroponics are used a lot outside of growing weed. Commercial production of herbs, salads and other greens is almost exclusively done with hydroponics, at least here in northern Europe, where light and heat are at a premium half of the year. Maintaining a greenhouse is expensive so maximizing the production per area per time is required for a viable commercial operation.