Indonesia's geographical condition, as a maritime country, has a wealth of natural resources in the form of water, which has the potential to support the economy in the aquaculture sector. One of them is the cultivation of freshwater fish ponds as has been carried out by the Maju Rukun Community Group (PokMas) in Ngerong Village, Pasuruan. Lack of equipment and knowledge in monitoring pond water conditions, resulting in problems with the fish nursery process. This is because water is a living medium for aquatic organisms, thus determining the survival of cultivated fish. Therefore, community service activities were held in the form of implementing an appropriate technology device "Arsenik version 2" and a mobile application that can be downloaded on Android to support water quality monitoring in aquaculture. In addition, socialization, training, and seminars regarding parameters of good pond water quality for fish farming were also provided to the Maju Rukun PokMas and the local community. Based on the positive response from the community, the implementation of the Arsenic device version 2 is considered very helpful in terms of monitoring the condition of pond water quality because it has informative parameter values and an easy presentation to understand so that the public can maintain the health of aquatic media for the aquaculture ecosystem in it.