The present invention relates to a water supply system for a fish farm, which supplies seawater to the inside of a water tank in a fish farm to raise fishes on a land and drains seawater from the water tank to the outside of the fish farm, more specifically, to a water supply system for a fish farm, which easily supplies and discharges water by installing a two-way pump in a connection line between the water tank and sea and uses water to clean a filter or a strainer or drains the water according to a pollution level by installing a pollution level sensor for measuring the pollution level waste water or drains the water. The water supply system for a fish farm according to the present invention includes a two-way pump in which one side of a first connection line connects to a water supply line, the other side of the first connection line connects to a drain line and which connects to a storage tank through a second connection line installed at the other side, a strainer which is installed on the front end of the water supply line and filters foreign substances included in seawater during inhaling seawater, a filter which is installed on one side of the strainer and filters seawater passes through the strainer, a water supply valve which controls the opening and closing of the water supply line and is installed on the other side of the filter, and a drain valve which controls the opening and closing of the water supply line, is installed in the drain line, and is operated by the drain valve sensor. A water supply valve sensor and the drain valve sensor are operated by a controller.본 발명은 육상에서 어류를 양식하기 위한 양식장의 수조 내부로 해수를 급수하고, 양식장의 수조 외부로 양식장의 수조 내부에 있던 해수를 배수할 수 있는 양식장의 급수 시스템에 관한 것으로, 더욱 상세하게는 공급원인 바다와 양식장 저수조 사이의 연결라인에 양방향펌프를 설치하여 급수와 배수를 원활하게 할 수 있는 것은 물론이고, 양방향펌프와 양식장 저수조의 사이에 저수조에서 배수되는 오,폐수의 오염도를 측정할 수 있는 오염도측정센서를 설치하여 그 오염도에 따라서 필터 및 스트레이너의 역세척에 활용하거나 또는 드레인으로 배출시킬 수 있는 양식장의 급수 시스템에 관한 것이다. 본 발명에 따르면, 일측에 설치된 양갈래로 나누어진 제1연결라인의 일측이 급수라인과 연결되고, 타측이 배수라인과 연결되며,
