Abstract
Calcareous water is one of the main problems in water resource management at the Mandalika Modern Nursery, because it has the potential to reduce the quality of irrigation water and inhibit the growth of plant seedlings. High lime content can affect the physical and chemical properties of water, such as pH, turbidity, and hardness, so effective water treatment efforts are needed. This study aims to analyze the quality of calcareous water based on physical and chemical parameters before and after the filtration process, and to evaluate the effectiveness of ultrafiltration technology in reducing lime levels in water used at the Mandalika Modern Nursery. The study was conducted using a field experiment method by taking water samples from two points, namely the reservoir water source and the water distribution network in the nursery office area. The parameters analyzed include pH, turbidity, and hardness. The research results showed that the application of the ultrafiltration method reduced pH by 3.29% (from 7.91 to 7.65), turbidity by 84.28%, and hardness by 33.67%. Although this technology does not completely remove lime from the water, ultrafiltration has proven effective in improving water clarity and reducing hardness, potentially supporting the provision of more suitable water for nursery activities.