What about growing genetically-engineered 'nutrient algae' in giant pools, and processing the resultant biomatter into bars for consumption? A layer of glass co

What about growing genetically-engineered 'nutrient algae' in giant pools, and processing the resultant biomatter into bars for consumption? A layer of glass could even be put over the pool to control conditions. If we're pursuing maximum nutrient and calorie output for minimum fertilizer and energy input, why look at traditional plants at all?