Dissolved oxygen plays an important role in bioremediation of aquaculture wastewater. In the present of aerobic condition, absorption and transformation of nutrient to generate biomass are
more apparent as compared to the anaerobic condition (Prathima Devi et al., 2012). The DO levels fluctuated throughout the treatment period in MA phytoremediation mode. This is mainly due to
the inconsistent equilibrium of the oxygen content in the wastewater. Excess DO would utilize for organic matter oxidation and also contribute to the shifting in the equilibrium of nitrite-nitrate
concentration (Godos et al., 2010). Thus, the more consistent patent could be noted in symbiotic MAeEM bioremediation where the continuous production of O2 was constant utilization by the population
of EM for their cell metabolism. In general, all modes of bioremediation were able to regulate the acidity of the aquaculture wastewater. The regulation of pH was important since it affect the equilibrium between ammoniaeammonium concentrations in the wastewater (Lekang, 2008). More acidic wastewater shifts the equilibrium towards the toxic ammonia whereas higher pH vice versa. Thus, the regulation in pH indirectly contributed to the conditioning of the aquaculture wastewater to sustain aquaculture
life.