What stopped me was, of course, the desire for the taste of food :-) but remember that spirulina contains every one of the nutrients required by the human body, even including one that is present only in mother's milk

You need to look for a dark colour -- rather, a bluish hue to the substance

Trust me -- and contact me if you have your doubts -- spirulina alone, with no other vegetables nor meat or anything else will make you thrive, leave alone survive!