The anaerobic process helps in converting the organic matter into biogas and reducing tthe BOD to about 3000 to 4000. The digested effluent with 3000 to 4000 BOD carrying dead and live bacterial biomass and with dark brown colour and continued offensive odour is withdrawn at regular intervals from the digestor and lead to open bioconversion ponds made of brick wall construction. The digested effluent is filled in the tank to a depth of about one metre and aerated continuously. Bacteria and alage are added to the aerated medium wihich help to bring down the BOD to less tha 1000 in 4-5 days. The biomass and the digested and aerated effluent becomes a rich medium for Golden fish.
Golden colour being a dominant character, it prevails in the offspring.
Through hormonal means all-male population is produced and cultured in the ponds. This being a hardy fish grows in a dense population at about 50,000 fingerlings per acre, reaching an optimum size of 400 gm per piece in six months. The fish is not only attractive in colour it has white meat, and tastes good when prepared in different forms. The undesired fishy odour is absent when it is cooked. The rich hearvest of about 50 tonnes per hectare per year gives an attractive return for the investment in the production control project.