Reciprocating biofilter for water reuse in aquaculture

The reciprocating biofilter is automatically dewatered at regular and frequent intervals, in contrast to the conventional upflow submerged biofilter which is continually inundated. Reciprocating biofilters were compared with submerged biofilters in terms of ability to maintain water quality in small-scale fish holding units. In the first trial the reciprocating filter systems averaged 35% more fish in terms of numbers, 59% more fish in terms of weight, and a 45% greater feeding rate. In the second trial the reciprocating filter systems averaged 29% more fish in terms of numbers, 33% more fish in terms of weight, and a 29% greater feeding rate. Superior performance of the reciprocating filters appeared to be the results of resistance to clogging and improved aeration of the filter substrate.