It depends on the exposure and your climate zone. An indoor Aloe plant can burn if growing in a hot sunny window so if the exposure is south or west, 2-5' is fine. In most climates, next to an east window is fine. A north exposure will most likely not provide the light needed to grow Aloe indoors. I live in Tucson, AZ which is one of the sunniest cities in the world so I definitely keep my Aloe vera out of south or west windows from May through October!