Title

COMPARATIVE EFFECTIVENESS OF ELECTROLYSIS AND BIOFILTRATION IN MANAGING WATER QUALITY FOR FRESHWATER NILE TILAPIA (Oreochromis niloticus) AQUACULTURE

Author(s)

Mariela V. Ramirez

Danica Marie E. Dicon

Glenn Manlupig

Affiliation

College of Agriculture and Forestry

Degree Program

Bachelor of Science in Agricultural and Biosystems Engineering

Contributor

Gether P. Enario, Ph.D. – Instructor/Adviser

Oliver S. Talip, Ph.D. – Chairman

Bernie P. Agustin, Eng. – Panel Member

Yunalyn Villantes, Ph.D. – Panel Member

Year

2026

Abstract

This study compared the effectiveness of electrolysis and biofiltration in managing water quality and supporting Nile tilapia (Oreochromis niloticus) production under tropical freshwater aquaculture conditions in Oroquieta City, Misamis Occidental. The experiment was conducted from January to March 2026 using a single-factor Randomized Complete Block Design (RCBD) with three treatments and three replications. Treatments consisted of: A1 – Control; A2 – Electrolysis (low-voltage electrolysis); and A3 – Biofiltration (a lava rock trickle tower biofilter). A total of 450 juvenile Nile tilapia fingerlings were stocked at 50 fish per tank across nine tarpaulin tanks (1.0 m × 2.0 m × 0.65 m) over an 8- week production cycle. Results showed that biofiltration (A3) consistently maintained the lowest Total Ammonia Nitrogen (TAN) concentrations (mean: 0.25 mg/L), significantly below the stress threshold of 0.50 mg/L, while electrolysis (A2) achieved intermediate ammonia control (mean: 0.44 mg/L) and the control (A1) exhibited progressive ammonia accumulation (mean: 0.94 mg/L). Biofiltration produced significantly superior fish growth performance, feed conversion efficiency, and survival rates compared to both electrolysis and control treatments. Economically, biofiltration also generated the highest net income and return on investment, while electrolysis offered moderate returns relative to its higher energy costs. The findings suggest that biofiltration using lava rock media represents a more reliable, cost effective, and sustainable ammonia management strategy for small- to medium-scale tropical Nile tilapia aquaculture, while electrolysis may serve as a complementary or emergency ammonia reduction measure under specific conditions.

Keywords

ammonia management, feed conversion ratio, fish growth performance, recirculating aquaculture system, total ammonia nitrogen