Established in 1993, the secret to Humpty Doo Barramundi’s success is a sustainable water treatment system with ‘little to no exchange with the surrounding waters’ forming the basis of a food chain. Brackish water is extracted from the tidal Adelaide River during the dry season months and pumped into a constructed wetland water treatment system that surrounds the production ponds which house the fish. As the fish producing ammonia and nitrites, these metabolic waste products feed into the constructed wetland water treatment system where they’re filtered through vegetation and broken down and consumed by naturally occurring bacteria and microalgae. As wastewater moves through the constructed wetlands nitrifying bacteria will begin to colonise. These bacteria will convert toxic ammonia and nitrites into nontoxic nitrates via oxidation.