A LOW-COST RECIRCULATION SYSTEM USING DISPOSABLE BEVERAGE CONTAINERS

A tank system with recirculating water designed for use with disposabl e plastic 3-L, beverage bottles is described. The system consisted of 100 culture units (2-L working volume in each), five 40-L tanks, and a n upwelling biofilter. The 40-L tanks were used to increase the total volume of the system, to allow operation of the filter when bottles we re not occupied, and for temporary storage of fish when treatments wer e pooled following screening. Each bottle received water from a common distribution manifold, and flow was adjustable from 0 to 1 L/min (0-3 0 water changes per hour). Bottles could be removed easily for replace ment or to facilitate study of fish. The system was designed to allow separation of treatments for genetic studies, but would be useful for experiments requiring replication of treatments or experimental units with minimal environmental variation.