This research is focused about the automation of water management and maintenance for cold water in aquarium. The researchers integrated different sensors in order to build a water management system for an aquarium. One of the sensor that the researchers used is the water level sensor for identifying if the water level in the aquarium that is being filled by the water pump is already in the right water level then it will stop from filling and if not, it will continue to fill the aquarium. The researchers also used the turbidity sensor that will be connected to the water pump, the turbidity sensor will open the water pump if the sensor detected that the clarity of water is less and the water will be pump out. Another sensor is water temperature. All the sensors are integrated to microcontroller to have the desired objectives of the research. The researchers used the PHP server for the user to monitor the data from all the sensors from the microcontroller. The data will be in table and it will be send to the PHP server where it is in data login. The data that can be monitored in the server is in every hour real time. This research is focused on the automation of water management and maintenance for cold water in an aquarium.