Comparative Assessment of the Water Quality of Four Types of Aquaculture Ponds under Different Culture Systems

Water quality of collapsible, concrete, earthen and natural ponds under different culture systems were assessed using of Photometer and tester. Temporal and spatial replications of samples were done in triplicates. Dissolved oxygen ranged between 4.6 to 6.8 mg/l, carbon dioxide 1.4 - 3.0 mg/l, nitrate 1.6 - 3.2 mg/l, phosphate 0.8 - 2.3 mg/l, calcium hardness 65- 100 mg/l, magnesium hardness 30 - 50 mg/l and total hardness 80 and 165 mg/l. Conductivity ranged between 346 - 472 μS/cm, total dissolved solids 232 - 316 mg/l, transparency 36 - 82 cm, alkalinity 105 - 245 mg/l, pH 6.35 - 8.03 and temperature 29.1 to 35.9 °C. Significant difference (P<0.05) was obtained among the parameters in the ponds showing the effects of the different culture systems on the water quality. Variations in the water quality was due to the presence of plankton and macrophytes found in earthen and natural ponds where semi-intensive and extensive culture were practiced, use of artificial feed in collapsible and concrete ponds where intensive culture was done, effects of respiration, photosynthesis and decomposition, source of water and materials used for the construction of the ponds. Water quality in the ponds under the different culture systems was good.