Dynamic study on the effect of calcium hydroxide and sodium bicarbonate treatment on the N/P ratio and plankton abundance

The development and growth of plankton in water is influenced by nutrients like nitrogen and phosphorus, which can be determined by the N/P ratio. Excess nutrients in water can lead to Harmful Algae Blooms (HABs). The application of Ca(OH)₂ and NaHCO₃ in water can control the nutrient elements and plankton abundance. This study was conducted to determine the dynamics of the N/P ratio value and plankton abundance through the application of a (Ca(OH)₂) and (NaHCO₃) dose of 1 ppm in a fish pond using the descriptive method. Before the application, the pond's nitrogen range was 1.04 - 1.06mg/l. After application, this increased to 1.07 - 1.39mg/l, while the phosphorus was 0.29 - 0.33mg/l before application. After the administration, the phosphorus increased followed by a decrease ranging from 0.30 to 0.62mg/l and 0.62 to 0.09mg/l respectively. The N/P ratio value before administration was 3.15 - 3.68mg/l and after the application, the N/P ratio decreased to an average value of 1.73 on day 4 followed by a subsequent increase to 14.70 on day 7. The average total plankton density from the three points was 789,583 ind/l before application. After the application, this decreased to 624,166ind/l. In conclusion, the application of Ca(OH)₂ and NaHCO₃ can stabilize the N/P ratio and decrease the total plankton density.