Studies on the Mass Culture of Phaeodactyylum. Iii. Small‐scale Experiments

Experiments in the mass culture of Phaeodactylum using 15‐L cultures, with inorganic fertilizers or sewage effluent as a nutrient source, are described. Following inoculation, growth may start immediately or after a short lag. A logarithmic growth phase is followed by a period of constant population density or by an immediate decline. Growth rate in the logarithmic phase varied from 0.25 division/day in winter to >1 division/day in summer. Purified sewage effluent, with or without salinity adjustment, is at least as good as inorganic fertilizers as a source of nutrients for the growth of Phaeodactylum.