Micro-algae, especially Chlorella vulgaris, produce a range of high-value substances and the biomass itself is used for purposes such as feeding in aquaculture. A lamellar settler was designed and built. Its suitability as a low-cost alternative to separate C, vulgaris was investigated. The settler operated semicontinuously in a laboratory photoreactor plant (total volume 9 l). A clearing of 30%-35% and a 50% increase in harvest outflow concentration were observed. The scaled up data for design and construction of a settler for a 200-1 production plant were elaborated.