A low-nutrient flow-through seawater facility is constructed on an open coast of Oahu, Hawaii. The facility complements a system of similar design existing in the high-nutrient environs of Kaneohe Bay. Present at each site are 12 tanks, each having a capacity of 160 gallons (600 liters) and each of which can be adjusted for flow-through rates of 0.1 to 15.0lpm. Biotic communities of varying complexity can be established by the natural recruitment of transplantation of organisms. Results are presented for a calibration test conducted from March through June 1975 to determine interfacility differences in source water chemistry, organism recruitment, and growth of biota in the tanks. (Author).