You will never find a better nutritional buy anywhere on the market than you will with both Spirulina and Chlorella . Ounce for ounce, your dollar goes farther toward providing the body with proper nutrition than any other foods available. There are a lot of different Spirulina brands on the market. A rule of thumb is to only buy Spirulina Pacifica that is Certified Organic, ISO 9200 (international standards) and Certified Kosher.