A system design and operational procedures for rearing yolk-sac larvae of Atlantic halibut (Hippoglossus hippoglossus) were developed from 1988 to 1992 at the Austevoll Aquaculture Research Station. The objective has been to develop a method for mass rearing of yolk-sac larvae. The method involves tanks with a cylindrical upper part and a conical lower part. Water inflow at the bottom and exit through overflow sieves provide continuous exchange of water and no dead volume. Over the 5-year period, detailed operating procedures have been established. The survival of larvae through the yolk-sac stage has improved each year, and survival rates from 60 to 80% were achieved in 1992.