Six algal species were fed singly and in combination with Pavlova lutheri, in both fresh and concentrated form, to 1-day-old Sydney rock oyster, Saccostrea commercialis, larvae for 6 days. Although a number of algal species produced high larval length increases, the best fresh diet consisted of P. lutheri and Isochrysis aff. galbana (T-iso). However, when concentrated to a paste and stored for 7-14 days at 4 °C, a combination of P. lutheri and Chaetoceros calcitrans produced greater length increases than any other fresh or stored, single or combined diet tested. Centrifugation and storage of algae prior to feeding had varied effects on the algal species tested, but it had no detected deleterious effects on any of the diatoms tested.