Abstract: An abalone farming system includes an indoor hatchery and an out-of-doors growout area which each utilize a plurality of horizontally elongated tanks in which the abalone are raised. These elongated tanks are stacked along a common vertical plane and arranged such that seawater provided at one end of an upper tank flows the entire length of that tank before cascading to a next lower adjacent tank, wherein the water flows the entire length of that tank before cascading to a next adjacent lower tank, and so forth until the water is discharged to a seawater discharge line. Each tank is provided with an air bar which extends the entire length thereof for aerating the seawater flowing through the tank, and a plurality of plates which are configured to increase the grazing area for the abalone and for dividing the area within the tank into distinct cells. A holding tank is utilized to supply water to both the hatchery and growout area.