Triple drain apparatus for an aquaculture system tank for reducing water inputrequirements and minimizing break-downof solids whereby the solids are larger and more concentrated when removedfrom a solids settling device. Water flow issplit by the apparatus into a side box fluid stream which flows into a sidebox coupled to the tank, and both a clean fluid streamand a high solids fluid stream which flow into a center drain. The centerdrain comprises a central stand pipe coupled to a cleanwater outlet, a sump coupled to a high solids fluid outlet and a collectionplate separating the tank and the sump. The center drainmay include a mortality trap coupled to a mortality outlet and the sump,whereby the collection plate separates the mortality trapfrom the sump, to provide means for easily removing dead fishes and largedebris from the tank.
