Water quality in an aquaponics system interconnected with a biofilter

Resumen

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

Design/Methodology/Approach: The organisms used in the aquaponics system were juvenile tilapia (Oreochromis niloticus) and wormseed (Chenopodium ambrosioides). The following physicochemical parameters of the water were analyzed: temperature, pH, dissolved oxygen, electrical conductivity, NH₄⁺, NO₂^-, and NO₃^-. Data generated in this work were subjected to an analysis of variance (ANOVA) and to the comparison of means (Tukey’s test, p<0.05).

Results: Recirculating tank water through the biofilter and plants reduced NH₄⁺ and NO₃^- by 31.6% and 18.5%, respectively. The total ammonia nitrogen in the tank did not exceed 0.022 mg L^-1. The fish survival rate was 100% and 725.8 g of wormseed were harvested. The wormseed did not show symptoms of mineral deficiency.

Study Limitations/Implications: Aquaponics production is still limited to small surfaces, as a consequence of the costs involved in its handling.

Findings/Conclusions: Water quality parameters of the tilapia (Oreochromis niloticus)-wormseed (Chenopodium ambrosioides) aquaponics system —interconnected through a biofilter with Luffa cylindrica— fulfilled the recommendations for such system.