Water quality in an aquaponic system interconnected with a biofilter

Abstract

Objective: To determine the water quality of an aquaponic system interconnected by a biofilter, using loofah (Luffa cylindrica) as an inert support.

Design/methodology/approach: The organisms used in the aquaponic system were juvenile tilapia (Oreochromis niloticus) and epazote (Chenopodium ambrosioides). The physical-chemical parameters analyzed in the water were: temperature, pH, dissolved oxygen, electrical conductivity, NH₄⁺, NO₂^- and NO₃^-. The data generated in this work were subjected to analysis of variance (ANOVA) and comparison of means (Tukey p<0.05).

Results: Recirculation of pond water through the biofilter and plants reduced NH₄⁺ and NO₃^- by 31.6% and 18.5%, respectively. In the pond, the total ammoniacal nitrogen did not exceed 0.022 mg L^-1. The survival of the fish was 100% and 725.8 g of epazotes were harvested, which did not show symptoms of mineral deficiency.

Limitations on study/implications: Aquaponic production is still limited to small areas due to the costs involved in its management.

Findings/conclusions: The water quality parameters of the tilapia (Oreochromis niloticus)-epazote (Chenopodium ambrosioides) aquaponic system, interconnected through a biofilter with Luffa cylindrica were maintained within the recommendations for said system.

Keywords: Biofilter, aquaculture, mineralization, ammonia