I took that from the Coralvue Q&A with @Luis Easyreefs , or at least tried to. Thanks for the correction.They are the same strains. The amount of phyto is different though, and their purpose is different as well. EasyBooster is designed to feed zooplankton and microfauna in the tank, while the phyto in EasySPS is integrated into the zooplankton for its antioxidant and misc properties.