Spirulina is an excellent source of nutrition for marine and freshwater invertebrates as well as vertebrates. It can significantly improve survival rates and size uniformity. This Spirulina is farm-raised in California and spray dried into a fine powder to preserve nutrition. It remains naturally micro-encapsulated for hours when rehydrated, and it also defilamentizes a few minutes after rehydration, making it easy for small larvae and zooplankton to eat. Filaments range from 8 to 100 microns in length. It has been deactivated, so it will not grow in your tanks, and is free from harmful bacteria and toxins.