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

Abstract

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.