UWSP-NADF Outdoor Covered Rearing Area Demonstration Building with Partial Recirculating Aquaculture System (PRAS)


UWSP-NADF has constructed a building that will be used for partial recirculating aquaculture system technology. The plumbing and tank design is specific for partial recirculation and will be tested on performance and efficiency.  This system may be a great innovation for farms, due to less need for costly equipment such as drum filters or biofiltraion systems while practicing sustainable aquaculture with water reusage. More to come on the design and efficiency of this system as this project progresses.

Week 1: Installation of outdoor cover by FarmTek. 

Decide on outdoor building (FarmTek), set up and secure.

Design system for tanks, piping, water inflow and drain system, including Recirculating Aquaculture System technology (RAS). Place tanks in building for layout of pipes and tanks to create a visual mapping of where systems and equipment will be placed. We worked with tank equipment supplier to design and test new 6 ft fiberglass tanks with integrated radial flow settler and dual drain setup for partial recirculation operation.

Week 2: Connecting to watermain and drain

Tank and piping layout for a preassembled drain piping for the tanks.  These pipes were all installed underground in the new building. Building was moved over to allow for construction of piping. Label pipes, organize and lay out. Begin construction. Trench dug through the middle for drain piping. Connect to watermain and drain. New watermain valve was installed to new building (9ft deep).

Week 3:  Connect Piping

Move building back to position. Run pipes up to where partial recirculation tanks will be inside building and cover the ends. Fill in and level area.

Week 4: Final Set up

Move and set up partial recirculation tanks inside building and connect to piping.




The Radial Flow Settler DesignRFS.jpg


>View Slideshow of the Radial Flow Settler


The new 6 foot tank design uses a built in Radial Flow Settler (RFS) which uses gravity to concentrate the solids of the water from the bottom tank drain, described in the slideshow below. Most of the waste from the tank leaves through the bottom drain. It is sent to the RFS to be concentrated and then flushed directly to effluent settling ponds. Most of the tank water flows out of the tank through the side sump. This cleaner water is sent to the recirculation sump where it will be pumped up to a degassing/aeration column to aerate and and strip Carbon Dioxide before returning to the tanks via a gravity distribution line. This is a partial recirculation system, which will recirculate 50-70% of the water. This system does not require a drum filter nor a biofilter which will greatly decrease equipment costs, while still practicing sustainable aquaculture by conserving water.


 New PRAS Lake Trout Building