Four chemical treatments with hydrogen peroxide (H2O2), copper sulfate (CuSO4), potassium permanganate (KMnO4) and chlorine (Cl2) were applied to the effluent pond water of a hybrid striped bass saltwater recirculating aquaculture system to compare their oxidation power. Four chemicals were applied at concentrations of 0 (control), 1, 5, 10 and 20 mg/l. An additional concentration of 40 mg/l was included in the chlorine treatment. Water samples from four hybrid striped bass ponds were tested with KMnO4 and Cl2. H2O2 did not reduce any of BOD, COD and chlorophyll-a, and copper sulfate was only effective on chlorophyll-a for the effluent pond. Removal efficiencies for chlorophyll-a by copper sulfate were 19.2%, 37.5%, 54.2% and 74.1% dose-dependently. Potassium permanganate effectively removed the BOD, COD and chlorophyll-a. The COD removal rates in four fish ponds varied from 15.9% to 31.6% at the concentration of 10 mg/l. Interestingly, Cl2 did not reduce the BOD and COD at all, but the BOD and COD instead increased drastically with increasing the Cl2 concentration. The pond water with the highest initial BOD and COD values among the fish ponds tested increased by 350% in the BOD and 150% in the COD at 20 mg/l. Furthermore, Cl2 did not significantly reduce any types of solid matter in this study, while KMnO4 seemed to reduce some extent volatile dissolved solid in the fish pond.

Introduction
Materials and Methods
    1. Pond water and chemical treatment
    2. Water quality and statistical analyses
Results and Discussion

• Jeonghwan Park(Department of Marine Bio-materials and Aquaculture, Pukyong National University, Busan 48513, Korea) Corresponding author
• Harry V. Daniels(Department of Applied Ecology, North Carolina State University, Raleigh, North Carolina 27695, USA)