A rectangular rearing tank is provided with an underflow outlet conduit extending to beneath a tank corner where it couples to a smooth-curved transitional conduit section forming a bottom part of a weir chamber through which both underflow and overflow effluent from the tank may be passed in a stress-relieving manner that avoids injury or death to fry and fingerlings.
An auto-flushing drainage filter system including a drum filter fastened to the lowest bottom of a fishpond, cylindrical brushes fastened inside the drum filter to remove debris and impurities from the water passing through, a first water pump to pump water from the fishpond through a clean water recycling pipe via the drum filter for circulation and filtration, a second water pump to pump a sudden rush of water from the fishpond into a drain pipe through the drum filter for carrying debris and impurities away from the drum filter.
