An experiment was conducted at the U.S. Fish and Wildlife Service's Coleman Station at Anderson, California, during 1949 to compare the growth of fingerling fall chinook salmon (Oncorhynchus tschawytscha) reared in large concrete ponds, in hatchery troughs, and in small circular tanks for a period of 24 weeks. The experiment was part of a search for an improved method for estimating, periodically, the total weight of fish held in the rearing ponds.