Which Aerogarden model would let me have sustainable lettuce for 2 people? Is it possible to have sustainable lettuce for 2 people?  We would probably eat around 2 small salads each per week.  My fear is that we'd eventually eat through all the leaves in no time and then have to wait a long time for more to grow.  Is there a Aerogarden model that would allow us to always have fresh lettuce available?

Thanks!